Stephen was the third son of Stephen, Count of Blois and Chartres, and Adela, daughter of King William I the Conqueror. He was reared by his uncle, King Henry I, and received vast lands in England, Normandy, and the county of Boulogne. With a number of other magnates he was pledged to support Henry's daughter, Matilda (q.v.), as successor to the throne. Nevertheless, many English nobles were reluctant to accept a woman ruler, and Henry's Norman subjects resented Matilda's marriage into an Angevin family. Consequently, after Henry I died in December 1135, the leading lords and bishops welcomed Stephen when he crossed the English Channel to claim the crown. In return for support from the pope, Stephen opened the way to increased papal influence in English political affairs.

Although Stephen was brave and energetic, his affable, mild-mannered nature prevented him from providing firm leadership. The lawlessness of his Flemish mercenaries and the desperate measures he took to build a party loyal to himself only alienated the barons. Hence, in 1138 Matilda's half brother, the powerful Robert, Earl of Gloucester, took up arms in support of Matilda's claim. At first Stephen scored several military triumphs, but he lost the support of the church when he arrested Bishop Roger of Salisbury and his relatives.

Seizing her opportunity, Matilda invaded England (September 1139). In an incredible display of chivalry, Stephen had Matilda escorted to Bristol, and she proceeded to bring most of western England under her control. Early in 1141 the Angevins captured Stephen in a battle at Lincoln. His cause might have been lost had not Matilda's arrogance provoked a rebellion of the citizens of London, where she had gone for her coronation. In November Stephen was exchanged for Gloucester, who had been captured by forces loyal to the king. Stephen gradually gained the upper hand, and in 1148 Matilda withdrew from England.

Although Stephen at this point exercised nominal control over most of the kingdom, he had neither the resources nor the will to suppress lawlessness and to mediate between warring nobles. He hoped only to secure the succession for his son, Eustace, but to do so he had to deal with Matilda's son, Henry of Anjou, who invaded England in January 1153 to claim his royal inheritance. When Eustace died in August, Stephen lost heart; he signed a treaty designating Henry as his successor. At Stephen's death, Henry ascended the throne as King Henry II.

voivod (prince) of Moldavia (1457–1504), who won renown in Europe for his long resistance to the Ottoman Turks.

With the help of the Walachian prince Vlad III the Impaler, Stephen secured the throne of Moldavia in 1457. Menaced by powerful neighbours, he successfully repulsed an invasion by Hungary in 1467, but in 1471 he invaded Walachia, which had by then succumbed to Turkish vassalage.

When the Ottoman sultan Mehmed II launched an attack on Moldavia, Stephen defeated the invaders near Vaslui (now in Romania; 1475). He was in turn defeated at Valea Albă (1476), and he barely managed to escape with his life. His search for European assistance against the Turks had little success, but his determination “to cut off the pagan's right hand” won him the acclaim of Pope Sixtus IV as the “Athlete of Christ.”

After 1484 Stephen had to contend not only with new Turkish onslaughts but also with Polish and Hungarian designs on Moldavian independence. Finally in the latter years of his reign he concluded with the sultan Bayezid II a treaty that preserved Moldavian independence but only at the cost of an annual tribute to the Turks. Though it was marked by continual strife, Stephen's long reign nonetheless brought considerable cultural development and was a period of great ecclesiastical building and endowment.