A student at the universities of Ingolstadt, Vienna, Kraków, and Paris, Aventinus served as tutor (1509–17) to the younger brothers of Duke William IV of Bavaria, during which time he published a Latin grammar and a history of the Bavarian dukes. In his famous Annales Boiorum (1517–21; “Bavarian Annals”), his anticlericalism and attachment to the Holy Roman Empire are clearly revealed. Aventinus never fully accepted Protestantism. His sympathy with the reformers and their teachings and his open disapproval of monasticism, however, was enough to cause his imprisonment for a short time in 1528.