In March 1362, Bertrand de Meyshones, archbishop of Naples, and three Dominican inquisitors initiated heresy proceedings against the Angevin prince Louis of Durazzo (1324–62). Louis stood charged with offering assistance to radical Franciscan dissidents who had rallied around him, and the trial formed part of a larger papal effort to root out Spiritual Franciscan heresy. Louis's birth and social standing were enough to make the trial noteworthy. The grandson of King Charles II of Naples (d. 1309), Louis belonged to a celebrated royal dynasty that ruled a papal fief (the Kingdom – Regno – of Naples) and identified itself as the champion of the Church and papacy. Louis was also the nephew of Élie de Talleyrand (1301–64), the cardinal protector of the Franciscan order and leader of a powerful faction within the papal curia. Louis was thus phenomenally well connected, with close ties to the papal hierarchy.

Equally extraordinary, Louis was already in prison for rebelling against his cousins Johanna of Naples and Louis of Taranto, who ruled Naples. Louis's rebellion was driven by desire for greater control over his family's wealth and holdings, and he had twice summoned Great Companies into the Regno, where they terrorized Neapolitan subjects. Louis's revolts garnered support, both within the Regno and outside it, and he portrayed himself as moved by orthodox religious zeal when he rebelled in 1356, during a period when Naples’ rulers were excommunicated for failing to pay the annual census they owed the Church. Louis of Durazzo was a rebel and a traitor in the minds of many contemporaries, but it was not obvious that he was a heretic. Yet, when he was finally captured and imprisoned in 1362, he and his supporters were examined not for political insurrection but for heresy. In a paradoxical twist of fate, a prince who had rebelled in order to recover his wealth after finding himself reduced to povero stato, in the words of Matteo Villani, faced trial for his support of apostolic poverty.