Cossa, Baldassare(bäldäs-sä`rā kôs`sä), c.1370–1419, Neapolitan churchman, antipope (1410–15; see Schism, GreatSchism, Great,
or Schism of the West,
division in the Roman Catholic Church from 1378 to 1417. There was no question of faith or practice involved; the schism was a matter of persons and politics.
..... Click the link for more information. ) with the name John XXIII. He had a military career before entering the service of the church. He was made a cardinal by Boniface IX (1402) and proved himself able, especially in financial matters. In 1408 he deserted Gregory XII and helped to bring about the Council of PisaPisa, Council of,
1409, unrecognized council of the Roman Catholic Church. It was summoned to end the Great Schism (see Schism, Great) by members of the colleges of cardinals of the two rivals, Gregory XII (in Rome) and Benedict XIII (Pedro de Luna, in Avignon).
..... Click the link for more information. to end the schism between the Roman and the Avignon popes. The council, declaring both Gregory XII and Benedict XIII deposed, set up a third claimant, Alexander V. On Alexander's death a year later, Cardinal Cossa was elected. Of the three rival "popes," John had by far the greatest following. He immediately sought the aid of SigismundSigismund
, 1368–1437, Holy Roman emperor (1433–37), German king (1410–37), king of Hungary (1387–1437) and of Bohemia (1419–37), elector of Brandenburg (1376–1415), son of Holy Roman Emperor Charles IV.
..... Click the link for more information. and helped elect Sigismund Holy Roman emperor. John allied himself with Louis IILouis II,
1377–1417, king of Naples (1384–1417), duke of Anjou, count of Provence, son and successor of Louis I of Naples. In 1389 the antipope Clement VII (Robert of Geneva) invested him with the kingdom, Lancelot, rival claimant of Naples, having been expelled in
..... Click the link for more information. of Anjou (later king of Naples) to make war on LancelotLancelot
, c.1376–1414, king of Naples (1386–1414), son and successor of Charles III. Almost his entire reign was consumed by his struggle with the Angevin rival king of Naples, Louis II, and with Louis's ally, the antipope John XXIII (see
..... Click the link for more information. of Naples and his ally Gregory XII. An ineffective council at Rome (1412–13) was followed by the Council of Constance (see Constance, Council ofConstance, Council of,
1414–18, council of the Roman Catholic Church, some of its sessions being reckoned as the 16th ecumenical council. It was summoned to end the Great Schism (see Schism, Great), in which three men were claiming to be pope—Gregory XII (since
..... Click the link for more information. ), which John convened under pressure from Sigismund. At the opening of the council he reluctantly promised (1415) to abdicate if his rivals would do so. Then, surreptitiously, he fled to the lands of his ally Frederick of Hapsburg. He was forced to return. The council formally deposed him, and he submitted. He was held prisoner in Germany until released by Martin V in 1418; he returned to Italy. He died cardinal bishop of Tusculum. In his lifetime he had a reputation for unscrupulousness and self-aggrandizement.