The cardinals who had turned against Pope Urban VI elected a new pope, Clement VII on 20 September 1378, which gave rise to the Western Schism. Louis acknowledged Urban VI as the legitimate pope and offered him support to fight against his opponents in Italy. As Joanna I of Naples decided to join Clement VII's camp, Pope Urban excommunicated and dethroned her on 17 June 1380. The pope acknowledged Charles of Durazzo, who had lived in Louis's court, as the lawful king of Naples. After Charles of Durazzo promised that he would not claim Hungary against Louis's daughters, Louis dispatched him to invade Southern Italy at the head of a large army. Within a year, Charles of Durazzo occupied the Kingdom of Naples, and forced Queen Joanna to surrender to him on 26 August 1381.