French theologian whose Institutes of the Christian Religion became the most comprehensive systematic theology of the Reformation and whose ecclesiastical ordinances for Geneva shaped Reformed church governance across Europe. His biblical commentaries and sermons constitute one of the most substantial exegetical legacies in Christian history.

Calvin's legacy is interpreted differently across traditions. Reformed tradition celebrates his theological brilliance; Catholic and critical accounts stress his coercive governance and the Servetus execution. Modern ecumenical dialogue has produced more nuanced assessments.

Born in Noyon, Picardy, Jean Calvin received a humanist legal education before converting to evangelical Christianity around 1533. Fleeing Catholic France, he published the first edition of the Institutes of the Christian Religion in Basel in 1536 — a work he expanded through four editions (final 1559) into the most comprehensive Protestant systematic theology.

Calvin spent brief time in Strasbourg under Martin Bucer before settling in Geneva, where — after an initial exile (1538-1541) — he established the Ecclesiastical Ordinances restructuring church governance around four offices: pastors, teachers, elders, and deacons. Geneva became a refuge for persecuted Protestants and a training ground for Reformed ministers.

Calvin's productivity was extraordinary: he preached nearly daily, wrote commentaries on most biblical books, produced thousands of surviving letters, and shaped Geneva's religious, educational, and civil institutions. His theology emphasized God's sovereignty, predestination, Scripture's authority, and the invisible church. His role in the execution of Michael Servetus for heresy in 1553 remains controversial and reflects the coercive religious uniformity of the era. Calvin's influence extended across Europe, shaping Reformed traditions from Scotland to Hungary to the Netherlands. He died on May 27, 1564.

• Reformer