The first comprehensive critical edition of the writings and letters of Andreas Bodenstein (1486–1541), also known as Karlstadt after his hometown, was one of the most influential Protestant theologians in Wittenberg alongside Martin Luther. He was the first to support his university colleague Luther both academically and publicly, and he was also the first to have a falling out with him. Reformation historical research has painted an ambivalent picture of him: while some viewed him as a traitor to Luther's cause, others saw him as a mediating figure between the circles of the Swiss Reformation and the Anabaptists. The edition, planned in 9 volumes, is being prepared by staff from the Göttingen Academy of Sciences, the Theological Faculty of the University of Göttingen, and the Herzog August Library in Wolfenbüttel. It includes a historical-critical edition of the entire transmission of church-historically significant sources with detailed commentary, extensive introductions, and historical contextualization.