 John XXII, wishing to organize a Crusade, sent him in 1318 as legate to the Count of Flanders, in the hope of establishing peace between the prince and the King of France.The mission was not successful, and his associates made charges to the pope against the legate, who, however, easily cleared himself.He was also a member of the commission appointed by John XXII to examine the writings of Petrus Olivi, whose books contained some errors of the Fraticelli.The Catholic Encyclopedia states that 'About this time he wrote "De causa immediata ecclesiasticæ potestatis" (Paris, 1506) against John of Pouilly, whose errors were condemned 25 July 1321.'