John Calvin's (Calvin, John) masterpiece, a summary of biblical theology that became the normative statement of the Reformed faith. It was first published in 1536 and was revised and enlarged by Calvin in several editions before the definitive edition was published in 1559.

The first edition, written in Latin and published in Basel, where Calvin was in exile, included a dedication to the French king Francis I. Calvin intended his work to be a statement of French Protestant beliefs that would refute the king, who was persecuting French Protestants and incorrectly calling them Anabaptists (radical Reformers who wished to separate the church from the state). It consisted of six chapters that discussed the Ten Commandments, the Apostles' Creed, the Lord's Prayer, the sacraments of Baptism and the Lord's Supper, disputed sacraments, and Christian liberty. Most of the themes of Calvin's mature thought were contained in the first edition.

The first French edition, prepared by Calvin and published in Basel in 1541, was the first great work in argumentative French prose. It influenced French thought and literary style.

The final edition, in Latin and published in Geneva in 1559, was more than four times longer than the first edition. It was organized into four books concerning Creator, Redeemer, Spirit, and church. The dominating themes dealt with God's sovereignty, his grace, and his redemption of undeserving sinners. This edition was published in French (1560), in English (1561), and eventually in many other languages.