The Italian political philosopher Marsilius of Padua (ca. 1275-1342) wrote Defensor pacis, the most important political treatise written in the late Middle Ages.

Marsilio dei Mainardini, who is known as Marsilius of Padua, was born at Padua. He was the son of a notary, and he received his early education in Padua, probably completing his arts degree and, perhaps, even a degree in medicine at the university there. Marsilius soon moved north to the leading university of his day, the University of Paris, where he became rector in 1313.

The years at Paris, first as a student, then as a teacher, were formative for Marsilius. He must have come into contact with the two most important theologians at Paris during that period, Durand of Saint-Pourçain and Peter Aureol. He certainly met the two leading Averroists, Peter of Abano and John of Jandun. Marsilius's teaching career culminated with...