Александр V
During the Western Schism, there were two claimants to the papacy. The Council of Pisa (1409) tried to end the schism by electing Alexander V as pope. However, neither the Avignon pope nor the Roman pope was willing to abdicate, so there were now three papal claimants. The Pisan pope Alexander V was succeeded by John XXIII, who abdicated in 1415 as part of a deal to end the schism.