The Protestant Reformation started in 1517 with the 95 Theses of the Augustinian monk and priest Martin Luther (1483-1546) against the sale of letters of indulgence. Martin Luther was excommunicated in 1521 by Pope Leo X and exiled to the Wartburg Castle, returning to Wittenberg in 1522. He translated the Bible into German, making an important contribution to the unification of the written German language. In 1525 he married Katharina von Bora and had six children. The Humanist Philipp Melanchthon (1497-1560) was his most important friend and colleague.