Martin Bucer, German Protestant reformer (b. 1491)
Martin Bucer (early German: Martin Butzer; 11 November 1491 – 28 February 1551) was a German Protestant reformer based in Strasbourg who influenced Lutheran, Calvinist, and Anglican doctrines and practices. Bucer was originally a member of the Dominican Order, but after meeting and being influenced by Martin Luther in 1518 he arranged for his monastic vows to be annulled. He then began to work for the Reformation, with the support of Franz von Sickingen.

Bucer's efforts to reform the church in Wissembourg resulted in his excommunication from the Catholic Church, and he was forced to flee to Strasbourg. There he joined a team of reformers which included Matthew Zell, Wolfgang Capito, and Caspar Hedio. He acted as a mediator between the two leading reformers, Martin Luther and Huldrych Zwingli, who differed on the doctrine of the Eucharist. Later, Bucer sought agreement on common articles of faith such as the Tetrapolitan Confession and the Wittenberg Concord, working closely with Philipp Melanchthon on the latter.

Bucer believed that the Catholics in the Holy Roman Empire could be convinced to join the Reformation. Through a series of conferences organised by Charles V, he tried to unite Protestants and Catholics to create a German national church separate from Rome. He did not achieve this, as political events led to the Schmalkaldic War and the retreat of Protestantism within the Empire. In 1548, Bucer was persuaded, under duress, to sign the Augsburg Interim, which imposed certain forms of Catholic worship. However, he continued to promote reforms until the city of Strasbourg accepted the Interim, and forced him to leave.

In 1549, Bucer was exiled to England, where, under the guidance of Thomas Cranmer, he was able to influence the second revision of the Book of Common Prayer. He died in Cambridge, England, at the age of 59. Although his ministry did not lead to the formation of a new denomination, many Protestant denominations have claimed him as one of their own. He is remembered as an early pioneer of ecumenism.