On 23 October 1327, Pope John XXII condemned as a heretic Louis of Bavaria, who had been elected in 1314 to the German throne. This act has traditionally been considered within the framework of the protracted political struggle between this monarch and three consecutive popes – John XXII, Benedict XII, and Clement VI – which spanned more than two decades. While the political dimension of this clash cannot be denied, this essay will re-focus attention on the heresiological dimension of Louis's condemnation in order to show how John's political and doctrinal concerns fused into a papal discourse that contained a whole array of heresy charges. These were not employed indiscriminately, but according to specific circumstances.

Political Inquisition, Demonic Magic, and the Matteo Visconti Affair

Open tensions between John XXII and Louis of Bavaria began about one year after the latter's victory against his Habsburg rival the ‘anti-king’ Frederick the Fair at the battle of Mühldorf on the river Inn (present day Bavaria) on 28 September 1322, as the pope still refused to recognize the kingship of the victor. Louis's troubles with the papacy did not end until his death on 11 October 1347, almost a quarter-century later. Despite numerous attempts to reconcile himself with the Church since the early 1330s, Louis died a heretic, without receiving absolution from the Church, a condition in which ‘he would have to appear in the moment of resurrection’ (‘Nec fuit absolutus per ecclesiam, et qualis fuerit, apparebit in resurrectione communi’), to quote the words of a contemporary chronicler, the Constance canon Henry of Diessenhofen. In modern historiography the condemnation of Louis of Bavaria as a heretic has been seen as an important moment in the political conflict between the German king (who after January 1328 also held the even more contested title of emperor) and the papacy. It is not by accident that Friedrich Bock coined the phrase ‘political inquisitorial process’ in a pioneering study of John XXII and his political foes. In Bock's words, Pope John turned ‘the weapons of the inquisitorial court against his political opponents, the Italian Ghibellines’, and also, ‘almost automatically, against the German king whose natural allies the Ghibellines had become’.