Marsilius of Padua (circa 1275 – 1342) was an Italian scholar, trained in medicine, who practiced a variety of professions. He was also an important 14th-century political figure. His political treatise Defensor pacis (The Defender of Peace), an attempt to refute papalist claims to a "plenitude of power" in affairs of both church and state, is seen by some authorities as the most revolutionary political treatise written in the later Middle Ages.