Antipope John XXIII

Italian bishop and Pisan antipope from 1410 to 1415

Baldassarre Cossa (died November 1419) was Pisan antipope as John XXIII (1410–1415) during the Western Schism. The Catholic Church today regards him as an antipope in opposition to Pope Gregory XII, whom it recognizes as the rightful successor of Saint Peter. John XXIII was also an opponent of Benedict XIII, who was recognized by the French clergy and monarchy as the legitimate pope.

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