There are twelve chapters in this treatise. The first concerns the purpose of the narrative. The second shows how the Roman Empire had remained based through the reigns of thirty-three emperors and for 345 years and five months invariably at Rome. The third demonstrates how the peoples of the East, namely, the Persians, Arabs, Chaldeans and other bordering nations, fell from the control of the Roman Empire. The fourth identifies the principal peoples who in the circumstances already described raised rebellion of this kind. The fifth treats the beginning and ordering of the transfer of the control of the Empire from the Greeks to the Franks. The sixth explains how Pepin was elevated, in the time of Zacharias, the Pope at Rome, from master of the palace to King of the Franks. The seventh relates how Pepin, King of the Franks, at the petitioning of the Roman church, marched to Italy against Astulphus, King of the Lombards, defeated him, and restored the temporal possessions of the Roman church. The eighth, how in the time of Pope Adrian, Charlemagne was made Patrician of the city and was granted the administration of the apostolic seat at Rome. The ninth, how the transfer of control of the Roman Empire from the Greeks to the Franks was effected. The tenth, how control of the Roman Empire was transferred from the Franks or Gauls to the Germans.

The beginning of the book entitled Defensor minor, edited by Master Marsiglio of Padua after the Defensor pacis major.

Chapter 1

[1] We have previously read in earlier works, according to the claims of the Master of the ‘Sentences’ [Peter Lombard], that priests have a certain power of binding and also of loosing, namely, of excommunicating sinners and cutting them off from spiritual as well as civil or temporal association [communicatio] and from fellowship with others of the faithful – powers which they call ‘jurisdiction’. It seems at least appropriate to examine what this jurisdiction is and how many types of it may be identified, and whether, according to any sense of the term, the jurisdiction of the emperor is due to bishops or priests.

[2] Just as the word indicates, therefore, ‘jurisdiction’ is the pronouncement of right [dictio iuris]; moreover, right is the same as law. Indeed, law is two-fold: it is sometimes divine, sometimes human. And taking law in its ultimate and proper meaning, as is written in Defensor pacis, Discourse 1, chapter 10, divine law is the immediate precept of God without human deliberation regarding voluntary human acts committed or omitted in the present world towards the best end or condition in the future world which human beings are suited to pursue. These are coercive precepts, I say, for transgressors in this world, under punishment or torment to be carried out in the future rather than the present world.

The reputation of Marsiglio of Padua (sometimes known by the Latinized version of his name, Marsilius) rests almost entirely on his authorship of the Defensor pacis (‘The Defender of the Peace’). Completed in 1324, the Defensor pacis has been an object of curiosity and controversy since its own century, both because it advocates a startlingly secularist concept of the origins and nature of the political community and because of its unwavering opposition to the powers and prerogatives of the church and the papacy as forces in temporal life. The fame of the Defensor pacis spread as its doctrines were borrowed by some later medieval authors, even as Marsiglio's teachings were also reviled in strident attacks by orthodox churchmen. When judged according to its innovations as well as its influence, the Defensor pacis must be counted in the first rank of contributions to the development of political theory during the Latin Middle Ages.

The Defensor pacis has consequently overshadowed Marsiglio's other writings. In addition to several works on metaphysical topics attributed to him, Marsiglio wrote two further political tracts: a recapitulation and synopsis of the main points of the Defensor pacis, entitled the Defensor [pacis] minor, and an historical survey of the origins and development of the Roman Empire, called De translatione Imperii (‘On the Transfer of the Empire’). The significance of these political writings is three-fold.