The German Protestant reformer Andreas Bodenheim von Karlstadt (ca. 1480-1541) was an early supporter of Luther. He later broke with Luther and became one of the more radical leaders of the Reformation.
Karlstadt was born at Karlstadt in Franconia. He attended the University of Erfurt, from which he received his bachelor's degree in 1502. He studied at Cologne and in 1504 went to the University of Wittenberg, where he rose to academic prominence. He won a doctor of laws degree at Siena in 1516. Introduced to the writings of St. Augustine by Martin Luther, Karlstadt soon shared the theological preoccupations that led to the start of the Reformation in 1517. In 1519 Karlstadt arranged the famous Leipzig Debates between himself and Johann Eck, but he made such a poor showing that his place had to be taken by Luther.
Karlstadt's career until 1519 was marked by considerable intelligence, a capacity for profound and original theological speculation, great energy, and fairness of mind. From 1519 until his death, however, other traits of character were also evident. His ambition and vanity became apparent, and his earlier tendency to follow intellectual and theological fashion drove him to theological and liturgical reforms which went far beyond those of Luther.
During Luther's seclusion in the Wartburg castle (1521-1522) Karlstadt made an abortive attempt to bring the Reformation to Denmark and then made himself the leader of the Reformation in Wittenberg. His doctrine of the common priesthood of all believers took the form of "the first Protestant communion," which he celebrated on Christmas Day 1521. In this rite Karlstadt omitted the consecration of the Host and allowed the laity to communicate in both species (bread and wine). These radical changes in Eucharistic doctrine and ritual led to his first break with Luther.
Karlstadt married in 1522 and associated briefly with Thomas Münzer and the Zwickau Prophets, who were ecclesiastical and social revolutionaries. In 1523 Karlstadt left Wittenberg to become the pastor of Orlamunde, but he was expelled from that post in 1524. He went to Strassburg and then to Basel, where his support of the Peasants' Rebellion endangered his life. Karlstadt had become reconciled with Luther, and he found shelter with him after the failure of the rebellion in 1525. But in 1527 he again broke with Luther on the question of the Eucharist.
With his wife and children Karlstadt then became a wanderer, proclaiming his theological doctrines and urging societal reforms somewhat similar to those proposed by the Anabaptists and Schwenckfelders. He finally found refuge in Zurich and in 1534 became a professor at the University of Basel. There Karlstadt continued his stormy career until his death of the plague.
There is no satisfactory biography of Karlstadt in English. There are useful discussions of his life in such histories of the Reformation as The New Cambridge Modern History, vol. 2: The Reformation: 1520-1599 (1958), and George Huntston Williams, The Radical Reformation (1962). Karlstadt's life is so entwined with Luther's that studies of the latter also deal with Karlstadt, as Robert Herndon Fife, The Revolt of Martin Luther (1957), and Walter G. Tillmanns, The World and Men around Luther (1959).
Pater, Calvin Augustine, Karlstadt as the father of the Baptist movements: the emergence of lay Protestantism, Lewiston, NY: E. Mellen Press, 1993.