Editing Antipope John XXIII (section)

=== Council of Pisa ===
Cardinal Cossa was one of the seven [[Cardinal (Catholicism)|cardinals]] who, in May 1408, withdrew their allegiance from [[Pope Gregory XII]], stating that he had broken his solemn oath not to create new cardinals without consulting them in advance. In company with those cardinals who had been following [[Antipope Benedict XIII]] of Avignon, they convened the [[Council of Pisa]], of which Cossa became a leading figure. The aim of the council was to end the schism; to this end they deposed both [[Gregory XII]] and Benedict XIII and elected a new pope [[Antipope Alexander V|Alexander V]] in 1409.<ref name=Kirsch/> Gregory and Benedict ignored this decision, however, so that there were now three simultaneous claimants to the [[papacy]].