Tomb of Antipope John XXIII - Antipope John XXIII

Antipope John XXIII

Antipope John XXIII had a complicated life, legacy, and relationship with Florence. Baldassare Cossa was a Neapolitan nobleman who grew up in Bologna. Pope Boniface IX elevated Cossa to the Archdiocese of Bologna in 1396 and made him a cardinal in 1402. After the Council of Pisa in 1409, Cossa encouraged rebellion against Pope Gregory XII, who refused to resign. Cossa was deprived of his cardinalate, but it was restored by Antipope Alexander V, who had been elected by the council.

Cossa succeeded Alexander V as John XXIII in 1410. John XXIII was acknowledged as pope by France, England, Bohemia, Prussia, Portugal, parts of the Holy Roman Empire, and numerous Northern Italian city states, including Florence and Venice; however, the Avignon Pope Benedict XIII was regarded as pope by the Kingdoms of Aragon, Castile, and Scotland and Gregory XII was still favored by Ladislaus of Naples, Carlo I Malatesta, the princes of Bavaria, Louis III, Elector of the Palatinate, and parts of Germany and Poland.

When Ladislaus of Naples conquered Rome in 1413, John XXIII was forced to flee to Florence. He was compelled by Sigismund, Holy Roman Emperor, to convoke the Council of Constance in 1414, although when the threat to his pontificate and possibly his person became apparent, he fled in 1415. Although he expected his departure would disperse the council, the members of which he called to join him under the protection of Frederick IV, Duke of Austria, it continued to operate where they were. As John XXIII tried to make his way towards the territory of John II, Duke of Burgundy, Frederick IV surrendered him to the custody of Sigismund and the Council, and he was imprisoned by Louis III.

In the meantime, the Council deposed John XXIII on May 29, 1415 and elected Pope Martin V on November 11, 1417; Martin V proceeded to Florence in February 1419. Cossa was ransomed by the Republic of Florence in 1419 (Louis III had abandoned the allegiance of Sigismund in 1417), as orchestrated by Giovanni di Bicci de' Medici. His ransom may have been a reward for past assistance to Florence, or a manoeuvre to put pressure on Martin V (still in Florence; he would arrive in Rome in September 1420), or both. Cossa had helped Florence conquer Pisa in 1405 in his capacity as Papal legate to Bologna and, as pope, had designated the Medici bank as the depository-general for the papal finances.

In Florence, Cossa submitted to Martin V on June 14, 1419 and was rewarded with a cardinal's hat on June 26, only to die on December 22. Although given the title of Cardinal Bishop of Tusculum, Cossa called himself "Cardinal of Florence".