After 1282 the signoria was composed of the 3 (afterwards 6) priori of the gilds, who ended by ousting the buoni uomini, while a defensor artificum et artium takes the place of the capitano; thus the republic became an essentially trading community, governed by the popolani grassi or rich merchants.
There are numerous manuscripts of the Defensor pacis extant.
But the scandal provoked by his Defensor pacis, condemned by the court of Avignon in 1326, lasted much longer.
While still practising medicine he entered into relations with another master of Paris, the philosopher John of Jandun, who collaborated with him in the composition of the famous Defensor pacis (1324), one of the most extraordinary political and religious works which appeared during the 14th century.
The conferring of the imperial crown by the Roman populace, the deposition of the pope by the same body, and the election of an anti-pope in the person of the Minorite Pietro da Corvara, translated into acts the doctrines of the defensor pacis.
King Henry himself in 1521 had deigned to write an abusive pamphlet against Luther, for which he had been awarded the magnificent title of Fidel Defensor by that cultured sceptic Pope Leo X.
Count Litzow in The Life and Times of Master John Hus (London and New York, 1909), pp. 5-9, gives a good abstract of the Defensor pacis and the relations of Marsilius to other precursors of the Reformation.
The Defensor pacis, as its name implies, is a work intended to restore peace, as the most indispensable benefit of human society.
But, above all, in an unpublished work preserved at Oxford, the Defensor minor, Marsilius completed and elaborated in a curious manner certain points in the doctrine laid down in the Defensor pacis.
Deposed by the head of the Empire (April 18), and a mendicant friar, Pietro de Corbara, raised by an imperial decree to the throne of St Peter (as Nicholas V.) after a sham of a popular election (May 12), all this was merely the application of principles laid down in the Defensor pacis.