body of laws made within certain Christian churches (Roman Catholic (Roman Catholicism), Eastern Orthodox, independent churches of Eastern Christianity, and the Anglican Communion) by lawful ecclesiastical authority for the government of both the whole church and parts thereof and of the behaviour and actions of individuals. In a wider sense the term includes precepts of divine law, natural or positive, incorporated in the canonical collections and codes.

Although canon law is historically continuous from the early church to the present, it has, as a result of doctrinal and ecclesiastical schisms, developed differing, though often similar, patterns of codification and norms in the various churches that have incorporated it into their ecclesiastical frameworks. The canon law of the Eastern (Eastern Orthodoxy) and Western churches was much the same in form until these two groups of churches separated in the Schism of 1054. In Eastern Christianity, however, because of doctrinal and nationalistic disputes during the 5th to 7th centuries, several church groups (especially non-Greek) separated themselves from the nominal head of Eastern Christianity, the patriarch of Constantinople, and developed their own bodies of canon law, often reflecting nationalistic concerns.

Canon law in the Western churches after 1054 developed without interruption until the Reformation of the 16th century. Though other churches of the Reformation rejected the canon law of the Roman Catholic church, the Church of England retained the concept of canon law and developed its own type, which has acceptance in the churches of the Anglican Communion.

Canon law has had a long history of development throughout the Christian era. Not a static body of laws, it reflects social, political, economic, cultural, and ecclesiastical changes that have taken place in the past two millennia. During periods of social and cultural upheaval the church has not remained unaffected by its environment. Thus, canon law may be expected to be involved in the far-reaching changes that have come to be anticipated in the modern world.

A church is defined as a community founded in a unity of faith, a sacramental fellowship of all members with Christ as Lord, and a unity of government. Many scholars assert that a church cannot exist without authority—i.e., binding rules and organizational structures—and that religion and law are mutually inclusive. Thus the calling of a church leader to office is regarded as important in the organizational structure and, like every other fundamental vocation in the churches that accept the validity of canon law, it is also viewed as sacramental and linked to the priesthood—which, in turn, involves a calling to leadership in liturgy and preaching. According to Roman Catholic belief, the mission of the college of Apostles (apostolic succession) (presided over by Peter in the 1st century AD) is continued in the college of bishops, presided over by the pope. Other churches may accept this view, without at the same time accepting the authority of the pope. The validity of canon law thus rests on an acceptance of this sacramental view and of the transmitted mission of the Apostles through the bishops.

Canon law has functioned in different historical periods in the organization of the church's liturgy, preaching, works of charity, and other activities through which Christianity was established and spread in the Mediterranean area and beyond. Canon law, moreover, had an essential role in the transmission of Greek and Roman jurisprudence and in the reception of Justinian (Justinian, Code of) law (Roman law as codified under the sponsorship of the Byzantine emperor Justinian in the 6th century) in Europe during the Middle Ages. Thus it is that the history of the Middle Ages, to the extent that they were dominated by ecclesiastical concerns, cannot be written without knowledge of the ecclesiastical institutions that were governed according to canon law. Medieval canon law also had a lasting influence on the law of the Protestant (Protestantism) churches. Numerous institutions and concepts of canon law have influenced the secular law and jurisprudence in lands influenced by Protestantism: e.g., marriage law, the law of obligations, the doctrine of modes of property acquisition, possession, wills, legal persons, the law of criminal procedure, and the law concerning proof or evidence. international law owes its very origin to canonists and theologians, and the modern idea of the state goes back to the ideas developed by medieval canonists regarding the constitution of the church. The history of the legal principles of the relation of sacerdotium to imperium—i.e., of ecclesiastical to secular authority or of church to state—is a central factor in European history.

Because of the discontinuity that has developed between church and state in modern times and the more exclusively spiritual and pastoral function of church organization, scholars in canon law are searching for a recovery of vital contact among canon law and theology, biblical exegesis (critical interpretive principles of the Bible), and church history in their contemporary forms. Canon-law scholars are also seeking a link with the empirical social sciences (e.g., sociology, anthropology, and other such disciplines), which is required for insight into and control of the application of canon law. The study of the history of canon law calls not only for juridical and historical training but also for insight into contemporary theological concepts and social relationships. Many sources, such as the documents of councils and popes, are often uncritical and found only in badly organized publications, and much of the material exists only in manuscripts and archives; frequently the legal sources contain dead law (i.e., law no longer held valid) and say nothing about living law. What does and does not come under canon law, what is or is not a source of canon law, which law is universal and which local, and other such questions must be judged differently for different periods.

The function of canon law in liturgy, preaching, and social activities involves the development and maintenance of those institutions that are considered to be most serviceable for the personal life and faith of members of the church and for their vocation in the world. This function is thus concerned with a continual adaptation of canon law to the circumstances of the time as well as to personal needs.

The early church was not organized in any centralized structure. Over a long period of time, there developed patriarchates (patriarch) (churches believed to have been founded by Apostles) and bishoprics (episcopacy), the leaders of which—either as monarchical bishops or as bishops with shared authority (i.e., collegiality)—issued decrees and regulatory provisions for the clergy and laity within their particular jurisdictions. After the emperor Constantine granted tolerance to Christians within the Roman Empire, bishops from various sees—especially from the eastern part of the empire—met in councils (e.g., the ecumenical Council of Nicaea). Though these councils are known primarily for their consideration of doctrinal conflicts, they also ruled on practical matters (such as jurisdictional and institutional concerns), which were set down in canons. In the West there was less imperial interference, and the bishop of Rome (the pope) gradually assumed more jurisdictional authority than his counterpart (the ecumenical patriarch of Constantinople) in the East. Throughout this period there were often conflicting canons, since there were many independently developed canonical collections and no centralized attempt to bring order out of them until the Middle Ages.

In addition to the New Testament, the writings of the Apostolic Fathers (Apostolic Father) (the second generation of Christian writers) and the pseudo-apostolic writings (documents attributed to but not written by the Apostles) contain the oldest descriptions of the customs existing in the East from the 2nd century until the 5th. The sources of all the others are the Doctrina duodecim Apostolorum (Doctrine of the Twelve Apostles, 2nd century?), the Didascalia Apostolorum (Teaching of the Apostles, 3rd century), and the Traditio Apostolica (Apostolic Tradition), attributed to Hippolytus, written in Rome about AD 220 but far more widely distributed in the East. From these documents the Constitutiones Apostolicae ( Apostolic Constitutions), in which 85 Canones Apostolicae (Apostolic Canons) were included, were composed about AD 400.

During the period that followed Constantine's grant of religious toleration, many synods (synod) held in the East legislated, among other things, various disciplinary rules, or canones. In addition to and in place of the law of custom, written law entered the scene. An ecumenical Council of Chalcedon (Chalcedon, Council of) (AD 451) possessed a chronological collection of the canons of earlier councils. This Syntagma canonum (“Body of Canons”), or Corpus canonum orientale (“Eastern Body of Canons”), was subsequently complemented by the canons attributed to other 4th- and 5th-century councils, canonical letters of 12 Greek Fathers and of the 3rd-century Latin bishop of Carthage, Cyprian, and the Constitutiones Apostolicae. With the exception of the last, the Trullo (supplementary) Council of Quinisextum (Quinisext Council), or the fifth and sixth councils (692), accepted this complex, along with its own canons, as the official legal code of the Eastern churches. The canons of the second ecumenical Council of Nicaea (787) and of the two councils (861 and 879–880) under Photius, patriarch of Constantinople, were added to that.

The systematic collections—and there were many of them—contained canons of councils, ecclesiastical laws (nomoi) of the emperors, or both together (nomocanons (nomocanon)). The first known Greek collection of canons that is preserved is the Collectio 50 titulorum (“Collection of 50 Titles”), after the model of the 50 titles of the work known as the Pandecta (“Accepted by All”), composed by the patriarch John Scholasticus about 550. He composed from the Novels (Novellae constitutiones post Codicem) of Justinian the Collectio 87 capitulorum (“Collection of 87 Chapters”). The Collectio tripartita (“Tripartite Collection”), from the end of the 6th century and composed of the entire Justinian ecclesiastical legislation, was the most widely distributed. The nomocanons were expressions of the fusion of imperial and church authority. The Nomocanon 50 titulorum (“Canon Law of 50 Titles”) from about 580, composed of the works of John Scholasticus, remained in use until the 12th century. The edition of the Nomocanon 14 titulorum (“Canon Law of 14 Titles”) was completed in 883 and accepted in 920 as law for the entire Eastern church.

The science of canon law was pursued together with the study of secular law, especially in the schools in Constantinople and Beirut. The Scholia (commentaries) on the Basilica, (Basilica) a compilation of all imperial law from the time of Justinian, promulgated by the Byzantine emperor Leo VI (reigned 886–912), influenced the method of commenting on and teaching canon law. The best-known commentators in the 12th century were Joannes Zonaras (Zonaras, Joannes) and Theodore Balsamon (Balsamon, Theodore). Matthew Blastares (Blastares, Matthew) composed his Syntagma alphabeticum (“Alphabetical Arrangement”), an alphabetic manual of all imperial and church law, in 1335 from their works.

The churches of Eastern Christianity that separated from the patriarchal see of Constantinople over a period of several centuries, but primarily during the 5th and 6th centuries, developed bodies of canon law that reflected their isolated and—after the Arab conquests in the 7th century—secondary social position. Among these churches are the Syrian Orthodox Patriarchate of Antioch (in Syria), the Ancient Church of the East (Nestorian) (the Assyrians), the Armenian Apostolic Church, and the Coptic Orthodox Church (Coptic Orthodox Church of Alexandria) (in Egypt). Another independent church is the Ethiopian Orthodox church.

Though these churches developed an extensive body of canon law throughout their histories, Western knowledge of their canon law has been very scant. In the 20th century, however, more than 300 manuscripts dealing with canon law were found in various isolated monasteries and ecclesiastical libraries of the Middle East by Arthur Vööbus, an Estonian-American church historian. These manuscripts cover the period from the 3rd to the 14th century and deal with ecclesiastical regulations of the Syrian churches. Included among these manuscripts are the following: “The Canons of the Godly Monastery of St. Mār Mattai” (630), 26 in number, concerning the jurisdiction of the metropolitan (an archbishop) over the monastery; “The Canons of the Holy Qyriaqos, Which the Patriarch Composed and the Synod of the Saints and Bishops with Him” (794), containing 46 canons dealing with ecclesiastical and moral discipline and with liturgical, cultic, and monastic matters; and “The Canons Which Were Composed by the Holy Synod Which Assembled in Bēt Mār Šīlā 【in the region】 of Serūg, and Which Consecrated Mār Dionysios as Patriarch of Antioch, the City of God” (896), which originally contained 40 canons, though only 25 remain, dealing with the election and examination of candidates for the hierarchy and clergy, the conduct of priests, marriage, pagan influences, and religious and ecclesiastical duties. These canonical collections come from the West Syrian churches. Other canonical collections of the East Syrian churches were published in the early part of the 20th century.

From about 300 until about 550, canon law in Western churches had a certain unity through the acceptance of the Eastern and North African councils and the binding factor of the papal decretal law (answers of popes to questions of bishops in matters of discipline), which did not exist in the East. The African canons, like the Eastern canons at Chalcedon, were read out at the councils of Carthage and, if confirmed, included in the Acts, which contained the newly enacted canons. Thus, at the third Council of Carthage (397), the Compendium of the Council of Hippo (393) was included. The collection of the 17th Council of Carthage (419) was soon accepted in all of the East and West. In Spain the canons of Nicaea I (325) and Chalcedon (451), African and south Gallican canons, and Roman decretals were taken over, as well as their own canons, but the later Hispana (Spanish collection) crowded out all earlier collections. The Council of Elvira (Elvira, Council of) (295–314) in Spain was the first that set up a more complete legislation, followed by Gaul in the first Council of Arles in 314. Texts from the East, Spain, and Rome, including the Collectio Quesnelliana (an early 6th-century canonical collection named for its publisher, the 17th-century Jansenist scholar Pasquier Quesnel (Quesnel, Pasquier)), circulated there. In about 480 Gennadius (Gennadius Of Marseilles), a priest from Marseille, wrote the Statuta ecclesiae antiqua (“Ancient Statutes of the Church”), principally inspired by the Constitutiones Apostolicae. A tendency toward the unification of canon law revealed itself most clearly in Italy against the disintegrating situation that existed between the Eastern and Western churches—i.e., the so-called Acacian Schism (484–519), occasioned by the patriarch Acacius of Constantinople and the emperor Zeno's neglect of the legislation of the Council of Chalcedon—and the breakup of the Western Empire soon after the fall of Rome (476), at the time of the 30-year “Gelasian renaissance,” beginning during the reign of Pope Gelasius I. There also existed in Rome translations of Eastern councils: Vetus Romana, versio Hispana (“Ancient Roman, Spanish Version”), Isidoriana, versio Prisca (“The Isidorian, Priscan Version”), and Itala (“Italian”). By far the most important is that of the Liber canonum (“Book of Canons”) of the 6th-century Roman theologian Dionysius Exiguus, about 500. The first two versions contain 50 Canones Apostolorum, Greek canons, and the African canons of the 17th Council of Carthage. Dionysius Exiguus also composed a Liber decretorum (“Book of Decretals”) from Pope Siricius to Pope Anastasius II. Together, the books form the Corpus (“Body”) or Codex canonum (“Code of Canons”).

Until the end of the 7th century a greater decentralization and less mutual contact occurred in the separate German kingdoms. Elements of German law (Germanic law) found their way into Roman canon law. The Collectio Avellana (“Avellan Collection”), written in Rome about 555, which was a Western nomocanon; the Collectio Novariensis (“Novarien Collection”); and the Epitome Hispanica (“Spanish Abridgment”) entered Italy from Spain. In Africa (North Africa) the first, albeit primitive, systematic collections appeared. These included the Breviatio canonum (“Abridgment of Canons”) of (Fulgentius) Ferrandus, deacon of the Church of Carthage (c. 546), and the Concordia canonum Cresconii (“Harmony of the Canons of Cresconius,” a 6th- or 7th-century author), a systematic compilation of the Dionysiana, subsequently found in different manuscripts in Gaul. There the collections were local ones; every cathedral and monastery had its own liber canonum. The church of Arles, the metropolis of southern Gaul, had the Liber auctoritatum (“Book of Authorities”; i.e., legal texts), a nomocanon of its privileges. The first systematic Gallic Collectio Andegavetis (“Andegavenan Collection”), from the end of the 7th century, was an attempt to unite the ancient law with the native.

In Spain, after the conversion of King Recared in 587, the church of the Visigothic (Visigoth) kingdom became a well-knit national church with a classical provincial structure under metropolitan jurisdiction, closely linked to the crown. The national councils of Toledo (Toledo, councils of) preserved the unity of law and respect for the ancient law. The Capitula (“Chapters”) of Martinus, bishop of Braga (c. 563), was included completely in the Hispana and was also copied outside Spain. The Collectio Novariensis was related to the Epitome Hispanica, the code of the hierarchy that was temporarily halted at the fourth Council of Toledo (633). The Hispana was recognized by popes Alexander III and Innocent III as the authentic corpus canonum of the Spanish church. Shortly before the Hispana, systematic indices (called tabula) were written and subsequently expanded into excerpta (“excerpts”) and finally into complete texts, the Hispana systematica (“Systematic Spanish 【Code】”). After the 10th century the Hispana was also called the Isidoriana, attributed to Isidore of Sevilla (Isidore of Sevilla, Saint), a Spanish encyclopaedist and theologian who was the author of the Etymologiae (“Etymologies”), a universally distributed early medieval book of doctrine.

The most disparate picture is offered by the church in the British Isles. The church there was concentrated around heavily populated monasteries, and discipline outside them was maintained by means of a new penitential practice. In place of ancient canons about public penance, the clergy and monks used libri poenitentiales (“penitential books”), which contained detailed catalogs of misdeeds with appropriate penances. They were private writings without official authority and with very disparate content. From the monasteries founded in Europe by the Irish (Ireland) monk St. Columban and missionaries of Anglo-Saxon (England) background, the libri poenitentiales spread throughout the continent, where once again new versions emerged. The Collectio Hibernensis (“Hibernian 【or Irish】 Collection”), of about 700, used texts from Scripture—mainly from the Old Testament—for the first time in canonical collections, and texts from the Greek and Latin early Church Fathers in addition to canons. The Liber ex lege Moysi (“Book from the Law of Moses”), an Irish work, drew exclusively from the Pentateuch.

The reorganization of the Frankish church began with the Carolingian (Carolingian dynasty) reform in the middle of the 8th century. The canon law was set down especially in the Capitularia (capitulary) ecclesiastica (“Ecclesiastical Articles”) of the prince, as well as in the Capitularia missionum (“Mission Articles”; i.e., instructions given by the prince to the bishops and abbots who visited in his name). The Capitularia (“Short Articles”) of Charlemagne, the founder of the Holy Roman Empire, and his son, the emperor Louis the Pious, were collected in 827 by the abbot Ansegisus. Following this model the bishops composed terse capitula, the oldest known diocesan statutes, for their clergy. The penance books were condemned and replaced by new ones that were more closely related to tradition. The reception of the Dionysiana and the Hispana is of importance for the transmission of the text and for the Carolingian cultural renaissance. In 774 Charlemagne received from Pope Adrian I a completed Dionysiana, the Dionysiana-Hadriana, which was accepted at a national synod in Aachen in 802 but never was adopted as an official national code. About 800 the Hadriana and the Hispana were developed into a systematic whole, the Dacheriana (canonical collection named for its 17th-century publisher, French scholar Jean-Luc d'Achéry)—the principal source of the collections before 850—which was of influence until the Gregorian reform in the 11th century.

After Louis the Pious, the central power among the Franks was increasingly divided among counts and barons. German law—which linked the right to govern with land ownership, without distinction between public and private law—expressed itself in the medieval forms of the system of private churches. This northern law looked upon dioceses, churches, and monasteries—with their rights and privileges—as lucrative possessions that deserved to be confiscated, by fraudulent means if necessary.

Such situations became the occasion in about 850 for the massive falsifications (False Decretals) (i.e., forgeries) of the pseudo-Isidorian collections: the Hispana Augustodunensis (“Spanish Collection of Autun”), the Capitula Angilramni (“Chapters of Angilramnus,” bishop of Metz), the Capitularia Benedicti Levitae (“Frankish Imperial Laws of Benedict the Levite,” a fictitious name), and the Pseudo-Isidorian Decretals. The central goal of the anonymous Frankish group of authors of these collections was to strengthen the position of the bishops and to rectify the poor condition of ecclesiastical-state affairs. This was accomplished by means of falsified and forged texts that were attributed to the esteemed authority of the old law (i.e., the popes) and the Carolingian princes. They did not have much influence on the real development of canon law, although later collections drew from them abundantly. Only the Magdeburg Centuriators, authors of the Centuries, a 16th-century Lutheran church history, denied the genuineness of all the decretals of pseudo-Isidore; the lack of authenticity of the other three works was discovered later.

Several collections appeared before AD 1000. About 882 decretals were organized in the Collectio Anselmo dedicata (“Collection Dedicated to Anselm”), a papally oriented, systematic work from northern Italy. In Germany the Libri duo de synodalibus causis et disciplinis ecclesiasticis (“Two Books Concerning Synodical Causes and Church Discipline”) of Regino, abbot of Prüm (906), was a bishops' manual for the judicial interrogation of jurymen during a visitation; and in France appeared the collection of Abbon, abbot of Fleury (c. 996), which defended the legal position of his monastery against the king and bishop. Intended as a doctrinal book for the young cleric, the “Decree of Burchard” (bishop of Worms from 1000 to 1025) became the canon-law manual in the cathedral schools and in the curias (administrative bureaucracies) of bishops and abbots in Germany, France, and Italy. Burchard was a promoter of moderate imperial reform. He did not reject the system of private churches; he only rejected the misuses proceeding from it, such as simony (buying or selling church offices) and the violation of celibacy.

The slogans of the Gregorian reformation (Gregorian Reform), initiated by Pope Gregory VII (reigned 1073–85), were libertas Ecclesiae (“liberty of the church”) and puritas Ecclesiae (“purity of the church”). These slogans advocated freedom from the system of private churches on all levels; freedom from papal dependence on the Roman nobility and emperor; freedom from dependence of the village priest on his senior (the beginning of the fight against investiture (Investiture Controversy)); and purity from simony and from the total collapse of celibacy (which was exhibited in the practice of hereditary parishes and bishoprics). Fundamental principles of Gregorian canon law included those stipulating that only canon law that is given or approved by the pope is valid; papal legates (representatives) stand above the local hierarchies and preside over synods; for possession of every ecclesiastical office, choice and appointment by church authorities is demanded, along with the exclusion of lay investiture; every form of simony makes the appointment invalid; and the faithful must boycott the services of married priests. New material was sought, especially for the confirmation of papal primacy, in archives and libraries. The principal new sources were the Breviarium of Cardinal Atto (c. 1075), the Dictatus Papae (“Dictates of the Pope”) of Gregory VII (c. 1075), the Collectio 74 titulorum (1074–76; “Collection of 74 Titles”), the collection of Bishop Anselm of Lucca (c. 1083) and that of Cardinal Deusdedit (c. 1085), and the Liber de vita Christiana (“Book Concerning the Christian Life”) of Bonizo, bishop of Sutri (c. 1090).

The investiture battle over the conflicting asserted rights of lay or ecclesiastical officials to invest a church official with the symbols of his spiritual office ended in France, England, and Germany (Concordat of Worms, 1122) in compromises. Gregorian law, which now seemed too strict, had to be reconciled with the established traditions. Ivo, bishop of Chartres (Ivo of Chartres, Saint) from 1091 to 1116, contributed to the settlement of the investiture problem by his political activities; his extended correspondence; and his three law collections: Tripartita (“Tripartite Collection”), Decretum (“Decrees”; i.e., collection of decrees or canons), and Panormia (collections of “All the Laws”), the last two practically a fusion of Burchard's Decree with Gregorian law. The famous Prologue, written by Ivo for either the Decretum or the Panormia, indicated for the first time a method by which the bishop must handle the conflicting strict and liberal texts, with justitia (“justice”) or misericordia (“mercy”). In his little tractates, written between 1070 and 1091, Bernold of Constance listed several criteria for the reconciliation of conflicting texts, including authenticity of the text; identity of the author; difference between law, counsel, and dispensation, between universal and local law; difference of time and place; and different meanings of a word. A Liège (Belgium) canon lawyer, Alger (Alger Of Liège), in his Liber de misericordia et justitia (c. 1105; “Book Concerning Mercy and Justice”), applied Ivo's criteria to the problem of the effect of sacraments administered by heretics and persons guilty of simony. The great medieval theologian Abelard (Abelard, Peter) developed the method of reconciling texts that are for or against a theological position in his Sic et non (1115–17; “Yes and No”). The same methods were applied by the first writers of glosses (commentaries or interpretations) at the law school in Bologna on the Pandecta of Justinian, which was rediscovered about 1070.

About 1140 the monk John Gratian completed his Concordia discordantium canonum (Gratian's Decretum) (“Harmony of Contradictory Laws”), later called the Decretum Gratiani (“Gratian's Decree”); it became not only the definitive canonical collection of the entire preceding tradition but also a systematic application of the scholastic method to all legal material. The Decretum dealt with the sources of the law, ordinations, elections, simony, law of procedure, ecclesiastical property, monks, heretics, schismatics, marriage, penance, and sacraments and sacramentals. Primitive as it was, it provided a foundation for systematic compilation of the legal material by the canonists and for the expansion of decretal law. It provided a basis for the education in canon law that began in the schools of Bologna, Paris, Orléans, Canterbury, Oxford, Padua, and elsewhere. It was accepted everywhere in the ecclesiastical administration of justice and government.

From the time that the Gregorian reformation introduced a more centralized ecclesiastical administration, the number of appeals to Rome and the number of papal decisions mounted. New papal laws and decisions, called decretals (decretal), first added to Gratian's Decretum, were soon gathered into separate collections, of which the best known are the Quinque compilationes antiquae (“Five Ancient Compilations”). The first, the Breviarium extravagantium (“Compendium of Decretals Circulating Outside”; i.e., not yet collected) of Bernard of Pavia, introduced a system inspired by the codification of Justinian, a division of the material into five books, briefly summarized in the phrase judex, judicium, clerus, connubium, crimen (“judge, trial, clergy, marriage, crime”). Each book was subdivided into titles and these in turn into capitula, or canons. This system was taken over by all subsequent collections of decretals. These compilations were the foremost source of the Liber extra (“Book Outside”; i.e., of decretals not in Gratian's Decretum) or Liber decretalium Gregorii IX (“Book of Decretals of Gregory IX”), composed by Raymond of Peñafort (Raymond of Peñafort, Saint), a Spanish canonist, and promulgated on September 5, 1234, as the exclusive codex for all of canon law after Gratian. On March 3, 1298, Pope Boniface VIII promulgated Liber sextus (“Book Six”), composed of official collections of Innocent IV, Gregory X, and Nicholas III and private collections and decretals of his own, as the exclusive codex for the canon law since the Liber extra. The Constitutiones Clementinae (“Constitutions of Clement”) of Pope Clement V, most of which were enacted at the Council of Vienne (1311–12), were promulgated on October 25, 1317, by Pope John XXII, but they were not an exclusive collection. The Decretum Gratiani, the Liber extra, Liber sextus, and the Constitutiones Clementinae, with the addition of two private collections, the Extravagantes of John XXII and the Extravagantes communes (“Decretals Commonly Circulating”), were printed and published together for the first time in Paris in 1500. This entire collection soon received the name Corpus Juris Canonici (“Corpus of Canon Law”).

The science of canon law was developed by the writers of glosses (legal glossator), the commentators on the Decree of Gratian (decretists), and the commentators on the collections of decretals (decretalists). Their glosses were based on the system used by Gratian: next to the texts of canons parallel texts were noted, then conflicting ones, followed by a solutio (“solution”), again with text references. In connection with this the glosses of other canonists were also introduced. In this way the apparatus glossarum, continuous commentaries on the entire book, arose. The glossa ordinaria (“ordinary explanation”) on the different parts of the Corpus Juris Canonici was the apparatus that was used universally in the schools. After the classical period of the glossators (12th–14th century), terminated by the work of a lay Italian canonist, John Andreae (c. 1348), came that of the post-glossators. In the absence of new legislation in the time of the Babylonian Captivity (1309–77), when the papacy was situated at Avignon (Avignon papacy), France, and the Great Schism (Western Schism) (1378–1417), when there were at least two popes reigning simultaneously, the commentaries on decretals continued, but with a larger production of special tracts; e.g., regarding the laws of benefices and marriage and of consilia (advice about concrete legal questions).

Toward the end of the Middle Ages decretal law ceased to govern. Medieval Christian society became politically and ecclesiastically divided according to the principle of cujus regio, ejus religio (“whose region, his religion”; i.e., the religion of the prince is the religion of the land). In Protestant areas the former Roman Catholic church buildings and benefices were taken over by other churches; and even in the lands that remained Roman Catholic the churches found themselves in an isolated position as secularization forced them to reorganize. With the end of feudalism, canon law dealing with benefices, chapters, and monasteries, which were closely bound to the feudal structure, changed. The territorial, material, and economic character of canon law and the decentralization allied with it disappeared. The decision of the reform councils from Pisa (1409) until the fifth Lateran Council (1512–17) affected, in particular, benefices, papal reservations, taxes, and other such ecclesiastical matters. In the same period various concordats (agreements) permitted the princes to intervene in the issue of ecclesiastical benefices and property. Canon law took on a more defensive character, with prohibitions regarding books, mixed marriages, participation of Roman Catholics in Protestant worship and vice versa, education of the clergy in seminaries, and other such areas of concern.

At the Roman Catholic reform Council of Trent (1545–63) a new foundation for the further development of canon law was expressed in the Capita de reformatione (“Articles Concerning Reform”), which were discussed and accepted in 10 of the 25 sessions. Papal primacy was not only dogmatically affirmed against conciliarism (the view that councils are more authoritative than the pope) but was also juridically strengthened in the conduct and implementation of the council. The central position of the bishops was recovered, over against the decentralization that had been brought about by the privileges and exemptions of chapters, monasteries, fraternities, and other corporate bodies that sprang from Germanic law, as well as caused by the rights granted to patrons. In practically all matters of reform the bishops received authority ad instar legati S. Sedis (“like delegates of the Holy See”). Strict demands were made for admission to ordination and offices; measures were taken against luxurious living, nepotism, and the neglect of the residence obligation; training of the clergy in seminaries was prescribed; prescriptions were given about pastoral care, schools for the young, diocesan and provincial synods, confession, and marriage; the right to benefices was purified of misuse; and the formalistic law of procedure was simplified.

The council gave the duty of execution of the reform to the pope. On January 26, 1564, Pius IV confirmed the decisions and reserved for himself their interpretation and execution, and on August 2, 1564, he established the congregation of the Council for that purpose. The congregations of cardinals (cardinal), which proceeded from the former permanent commissions of the consistorium (the assembly of the pope with the Sacred College of Cardinals), were organized by Pope Sixtus V in 1587. Since then the administrative apparatus of the Roman Curia has consisted of congregations of cardinals together with courts and offices. This apparatus made it possible for the Latin church to acquire a uniform canon law system that was developed in detail.

Expansion of the church brought with it expansion of the ordinary hierarchical episcopal structure. This was true also for the new colonies under the right of patronage of the Spanish and Portuguese kings. In the other mission areas and in the areas taken over by the Protestants, where the realization of the episcopal structure and the decretal law adopted by Trent was not possible, the organization of mission activity was taken from missionaries and religious orders and given to the Holy See. The Sacred Congregation for Propagation of the Faith (the Propaganda) was established for this purpose in 1622. Missionaries received their mandate from Rome; the administration was given over to apostolic vicars (bishops of territories having no ordinary hierarchy) and prefects (having episcopal powers, but not necessarily bishops) who were directly dependent on the Propaganda, from which they received precisely described faculties. A new, uniform mission law was created, without noteworthy native influence; this sometimes led to conflict, such as the Chinese Rites Controversy in the 17th and 18th centuries over the compatibility of rites honouring Confucius and ancestors with Christian rites.

The First Vatican Council (Vatican Council, First) (1869–70) strengthened the central position of the papacy in the constitutional law of the church by means of its dogmatic definition of papal primacy. Disciplinary canons were not enacted at the council; but the desire expressed by many bishops that canon law be codified did have influence on the emergence and content of the code of canon law.

Since the closing off of the Corpus Juris Canonici there had been no official or noteworthy private collection of the canon law, except for the constitutions of Pope Benedict XIV (reigned 1740–58). The material was spread out in the collections of the Corpus Juris Canonici and in the generally very incomplete private publications of the acta of popes, of general and local councils, and the various Roman congregations and legal organs, which made canon law into something unmanageable and uncertain. The need for codification was recognized even more because of the fact that since the end of the 18th century, secular law had undergone a period of great codification. Several private attempts to do this had met with little success.

On March 19, 1904, Pius X (Pius X, Saint) announced his intention to complete the codification, and he named a commission of 16 cardinals, with himself as chairman. Bishops and university faculties were asked to cooperate. The schemata of the five books that were prepared in Rome—universal norms, personal law, law of things, penal law, and procedural law—were proposed in the years 1912–14 to all those who would ordinarily be summoned to an ecumenical council, and with their observations were then reworked in the cardinals' commission. The entire undertaking and all the drafts were under the papal seal of secrecy and were not published. Meanwhile, Pius X introduced various reforms that were to a great degree the results of the commission's work. In July 1916 the preparations for the Codex Juris Canonici (“Code of Canon Law”) were completed. The code was promulgated on Pentecost Sunday, May 27, 1917, and became effective on Pentecost Sunday, May 19, 1918.

In contrast to all earlier official collections this code was a complete and exclusive codification of all universal church law then binding in the Latin church. Out of fear of political difficulties, a systematic handling of public church law, especially what concerned the relations between church and state, was omitted. Its main purpose was to offer a codification of the law, and only incidentally adaptation, and so it introduced relatively little that was new legislation. The 2,414 canons were divided into five books that no longer followed the system of the collections of decretals but did follow that of the Perugian canonist Paul Lancelotti's Institutiones juris canonici (1563; “Institutions of Canon Law”), which in turn went back to the division of the 2nd-century Roman lawyer Gaius's Institutiones—one section on persons, two sections on things, and one section on actions—and was based on the fundamental idea of Roman law; i.e., subjective right. In some editions the sources that were used by the editors were indicated at the individual canons. With the publication of the codex these sources belonged to the history of the law. Older general and particular law, in conflict with the codex, was given up and, insofar as it was not in conflict with it, served only as a means for interpreting the code. The old law of custom in conflict with the code and expressly reprobated by it was rendered null; when not reprobated and 100 years old or immemorial it could be allowed by ordinaries for pressing reasons. Acquired rights and concordats in force remained in force. With this change, an independent science of the history of canon law became necessary, in addition to the dogmatic canonical science of canon law on the basis of the code.

In order to ensure the unity of the codification and the law, a commission of cardinals was established on September 15, 1917, for the authentic interpretation of the new code. At the same time it was decided that the cardinals' congregations should no longer make new general decrees but only instructions for the carrying out of the prescriptions of the code. Should a general decree appear necessary, it was determined, the commission would formulate new canons and insert them into the code. Neither of these decisions was carried out. Only two canons were altered and congregations promulgated numerous general decrees. New papal legislation complemented and altered the law of the code.

Catholic Eastern churches (churches in union with the Roman Catholic church) retain their own traditions in liturgy and church order, insofar as these are not considered to be in conflict with the norms taken by Rome to be divine law. In 1929 Pius XI set up a commission of cardinals for the codification of canon law valid for all Uniate churches in the East. In the following year a commission was established for the preparation of the codification and another for the collection of the sources of Eastern law, in which experts of all rites were involved. These collections were published in three series, begun respectively in 1930, 1935, and 1942.

In 1935 the preparatory commission became the Pontifical Commission for the Redaction of the Codex Juris Canonici Orientalis (“Code of Oriental Canon Law”). The cooperation of all Eastern ordinaries (bishops, patriarchs, and others having jurisdictions) was requested, and the drafts of the various documents were sent to them. Thereafter four parts were published: in 1949, on marriage law; in 1952, on the law for monks and other religious, on ecclesiastical properties, and a title De Verborum Significatione (“Concerning the Meaning of Words,” a series of definitions of legal terms used in the canons); and in 1957, on constitutional law, especially of the clergy. The still-incomplete codification followed the Latin code with the assimilation of the authentic interpretation and with textual corrections, as well as with the insertion of the general law proper to the Eastern churches, including the Orthodox churches, regarding the patriarchs and their synods, marriage law, the law of religious, and other matters. The promulgation was made only in Latin in the Acta Apostolicae Sedis, the official organ of the Holy See. The Catholic Eastern churches came under the Congregation for the Eastern Churches that was established on January 6, 1862, by Pius IX as part of the Propaganda Fide; it was made independent by Benedict XV on May 1, 1917, and expanded considerably by Pius XI on March 25, 1938. Roman legislation as well as the jurisdiction of a congregation of the Roman Curia was criticized as being incompatible with the traditional autonomy of the Eastern churches in legislation and administration.

Fundamental to the development of canon law in the Roman Catholic church is the Second Vatican Council's (October 11, 1962–December 8, 1965) vision of the church as the people of God. In this connection the former concept of the church as societas perfecta (“perfect society”), founded by Christ through the mission of the Apostles and their successors, to which one belongs through subjection to the hierarchy, is replaced by a vision of the church as a community in which all possess the sacramental mission to live and proclaim the Gospel, and all have a function in the service of the whole. The legislative and administrative functions remain related to the hierarchy, but this is much more expressly seen as a service for the religious life of the community. The idea of collegiality, resting on the recognition of the vocation received by each one from the Lord, works itself out in the relationship existing among the bishops and with the pope, as well as that of the bishops with the clergy and of the clergy with the laity. Related to this is a tendency to coresponsibility and the democratization of the church structure and also an autonomy for the laity to exercise individually and collectively the Christian mission proper to them; namely, to bring the spirit of Christ into the secular life of humankind. The right of clergy and laity to a share in the leadership of bishops and pope is recognized. The vision of the people of God as sacramentum mundi, a sign of redemption for the entire human race, gave a new insight into the relationships with the Protestant churches, the other world religions, and the nonreligious atheistic and humanistic movements. In this view, freedom of religion and philosophy became the most fundamental right of humanity.

From a schematically chronological survey of the principal conciliar and post-conciliar legislation a new era apparently began for canon law. In 1960 the Secretariat for Promoting Christian Unity was established. Three years later various faculties, previously reserved to Rome, were given to the bishops; and in 1964 actions were undertaken for the reorganization of the papal commission for communications media, establishment of the Secretariat for Non-Christians, and lifting of the prohibition against cremation. Other legislative changes indicating a new era included several regulations that could not have been proposed with any possibility of their being accepted prior to Vatican II. In 1965, for example, preeminence in the Sacred College of Cardinals was given to Eastern patriarchs, after deacon and subdeacon and after the cardinals of the dioceses of the province of Rome; in the same year the Secretariat for Non-Believers was established and the Holy Office (formerly the Inquisition) became the Congregation for the Doctrine of the Faith, with emphasis on the positive fostering of theological research. In 1966 greatly reduced prescriptions for fasting and abstinence were adopted, the Index of prohibited books became a moral guide instead of obligatory law, and in implementation of the conciliar degree on the episcopal office, the principle according to which ordinaries (e.g., bishops) dispense from universal laws only when this is allowed by law or special faculties was replaced by the principle that ordinaries can always dispense unless it is explicitly reserved to Rome—and such reserved dispensations in question are indicated.

In addition to these changes, further canonical regulations were accepted. New regulations for mixed marriages were adopted in 1966. Norms were established for the implementation of the conciliar decrees on the office of bishops and priests; missionary activity; personal and material aid to needy churches; introduction of priests' councils and pastoral councils of priests, religious (i.e., monks and nuns), and laity as advisory groups for bishops; international episcopal conferences and their mutual relationships; and other concerns. From 1967 to 1970 more changes were made in canonical regulations—e.g., in 1967, total revision of the norms for indulgences, establishment in the Roman Curia of the council of laymen and the study commission Justitia et Pax (“Justice and Peace”), new dispensation rights for Eastern bishops, directory for ecumenical cooperation with Christian churches, regulation of the office of the diaconate to include married men, and reorganization of the Roman Curia; in 1970, a mandate to the secretary of state to discuss with the world episcopacy the question of celibacy and ordination of married men in areas that need priests.

Characteristics of the new regulations included searching for structures to allow all members of the church to have a voice in ecclesiastical decision making and decentralization and autonomy of local churches. Regulations from Rome were kept to the general, with ample room for local adaptation. In addition, new regulations were to be enacted only after extensive and open inquiry and test by experience, with possibilities for experimentation. In place of regulations of religious behaviour, canon law was becoming an ordering of the cooperation of all members of the Roman Catholic church for the realization of its mission in the world.

On January 25, 1959, John XXIII announced the revision of the church's code. On March 28, 1963, he set up a commission of cardinals for that purpose. On April 17, 1964, Paul VI named the first consultants. No publicity was given to the commission's work, but the first episcopal synod (September 30–October 4, 1967) gave its approval to a document in which several principles for the revision were indicated (Principia quae Codicis Juris Canonici Recognitionem Dirigant 【“Principles Which Guide the Recognition of the Code of Canon Law”】): the juridical character of the code ought to be preserved and not, as some wished, be limited to a rule for faith and morals; canon law for the area of each one's personal conscience should be maintained, but conflicts between law for conscience and public law ought to be avoided, especially in marriage and penal law; as a means to stimulate pastoral work it was recommended that the laws be expressed in a spirit of love, fairness, and humanity; no binding prescriptions were to be given where admonition and counsel suffice; pastoral workers were to be given more discretionary powers, and greater freedom was to be given to bishops, especially in mission areas; laws were to be such that ample possibility is given for local adaptation, carrying through the principle of subsidiarity (i.e., that nothing should be committed to higher organs that can be accomplished by individuals or lesser or subordinate bodies), however, with care to retain the unity of law and jurisdiction; regulation of administrative jurisdiction and in principle public jurisdiction; distinction of legislative, administrative, and judicial functions; limitation of punishments, in particular limitation of punishments incurred automatically upon commission of the offense to very few and very serious crimes. On May 28, 1968, the commission approved a preliminary division of the new codex.

As the drafts of the various parts of the new code became available, a vast process of consultation was initiated. The departments of the Roman Curia, the local bishops and their regional conferences, the heads of religious institutes, and university faculties of canon law were invited to evaluate the schemata and offer suggestions for their improvement. This lengthy procedure was completed in 1982.

The second Codex Juris Canonici (Canon Law, Code of) in history for the Catholics of the Latin rite was promulgated by Pope John Paul II on January 25, 1983, and entered into effect on November 27, 1983. It contains 1,752 canons divided among seven books. The books are: (1) “General Norms,” concerning the operating principles of canon law, definitions of juridical persons, and ecclesiastical offices; (2) “The People of God,” describing the rights and duties of the faithful in general and of clerics and laypersons in particular, as well as the organizational structures of the church, papacy, episcopal college, Roman Curia, particular churches, and institutes of consecrated life; (3) “The Teaching Office of the Church,” concerning catechetical and missionary activities, schools, and media of communication; (4) “The Sanctifying Office of the Church,” describing sacraments and worship in all their forms; (5) “The Temporal Goods of the Church,” defining ownership and administration of property, contracts, and charitable foundations; (6) “Sanctions in the Church,” describing various crimes, delicts, and penalties; and (7) “Procedures,” outlining the administration of justice by ecclesiastical courts, various quasi-judicial actions, and remedies.

The declared intention of the drafters of the new code was to give practical effect to the theological insights of the Second Vatican Council. The emphasis in the new law is on the universal people of God, and the governing power of the hierarchy is presented as a call to serve. The fundamental rights of the faithful are clearly asserted, and their active participation in the life of the church is encouraged. An effort was made toward decentralization, with local bishops enjoying more autonomy. Despite criticism from some scholars and clerics that the new code remains conservative on certain issues, it is recognized that the body of the law is permeated by an ecumenical spirit and displays a respect for the freedom of conscience and religious conviction of every human being. With the new code the hermeneutics of canon law have changed significantly. Apart from the strictly legal transactions, creating enforceable rights and duties (as in matters of property), the application of the laws must be guided and moderated according to pastoral needs.

A process similar to that used for the preparation of the new code for the Latin church was in progress during the 1980s for all the Eastern Catholic churches. The first draft of the new, unified code of laws was completed in 1986. It consisted of 1,561 canons, organized into 30 titles. The institutions and structures of the Uniate churches were supported; the right to worship according to their own liturgical traditions was confirmed. The dignity and power of the patriarchs and of the major archbishops were recognized. The importance of synodal government at different levels was affirmed. Overall, the major themes found in the draft were the same as the ones in the Latin code (although arranged in a different order); in matters of common interest many canons were taken word-for-word from the Latin code. The process of consultation over this schema, once completed, is likely to bring about many changes in the proposed canons. The task of codifying in a single volume the laws of so many churches—having different historical memories, rooted in various cultures, and without a common language—is a daunting one, even if they all profess the same faith and are in communion with Rome.

The Anglican Communion embraces the Church of England (England, Church of) and its affiliated churches. Since the submission of the clergy demanded by King Henry VIII and the Act of Supremacy in 1534, in which the Parliament recognized him as supreme head of the Church of England and which was renewed by Queen Elizabeth I, the law of the English church rests on the supremacy of the prince or of the Parliament. It is theoretically accepted that, outside the law determined by the English synods in the ancient independent national churches, only the principles of the jus ecclesiasticum commune (“common ecclesiastical law”) are binding, but other norms, promulgated by popes and councils, are accepted only to the extent that they were accepted by English ecclesiastical or secular courts. For practical purposes the development of church law in the English church is held by some canonists (usually Roman Catholic) to be not canon law but the ecclesiastical law of the state. The hierarchy has the power to ordain by virtue of the apostolic succession, which was preserved—according to the Anglican view—by the consecration of Matthew Parker as archbishop of Canterbury (1559), but it does not possess legislative authority.

The ecclesiastical provinces are administered by the Convocations of Canterbury and York, each of which consists of an upper house of bishops and a lower house of clergy. In 1919 a Church Assembly was established by the Enabling Act. In 1970 the Church Assembly was replaced with the General Synod, which is responsible for the government of the church. The General Synod consists of three houses: the House of Bishops and the House of Clergy are both formed from the upper and lower houses of the Convocations of Canterbury and York, respectively; the House of Laity is the Synod's lower house. The Synod has authority over liturgical, doctrinal, ecumenical, and financial matters within the church. It legislates according to the Canons of the Church of England or by measure, a proposal relating to any matter (with the exception of dogmas of faith) concerning the Church of England that the Synod presents to Parliament and whose enactment requires both parliamentary approval and royal assent. Lambeth Conferences (Lambeth Conference), which have been held approximately every 10 years since 1867 and which involve all Anglican bishops from throughout the world, do not have legislative authority.