This volume makes available for the first time in English the writings about the Holy Roman Empire by Marsiglio of Padua (c.1275–1342), one of the most influential and original political thinkers of the Latin Middle Ages. Included are two major texts. The Defensor minor is a restatement and defence of the doctrines of Marsiglio’s best known work, the Defensor pacis. As such it adds to our understanding of his previous thought while giving new dimensions to his theory. De translatione imperii (On the Transfer of the Empire) is a form of appendix to the Defensor pacis, in which Marsiglio’s general intellectual framework is applied to an historical assessment of the legitimacy of the exercise of imperial power by the German king outside the authorisation of the pope.