The Great Western Schism

Gregory XI died at Rome in March 1378, and the cardinals met in conclave in the palace where he had died. They chose Bartholomew, archbishop of Bari, who took the name Urban VI, and in a letter of 8 May they announced that they had elected him freely and unanimously and had crowned him at Easter in St Peter’s (Knighton, Chronicle vol. 2, pp. 128–129).

In August cardinals who had elected him declared the election void. Armed Romans, they now said, had surrounded and entered the palace and threatened to kill them unless they chose a Roman or an Italian, and they had named the archbishop out of fear (Declaration of the Cardinals (1378)). Catherine of Siena wrote to three Italian cardinals that this was false: they had chosen Urban canonically, done him reverence and asked favours of him, and had now made an antipope (Catherine of Siena, Letters To Three Italian Cardinals). The English chronicler Knighton records that the cardinals who left Urban went to Avignon and set up Robert of Geneva as Pope Clement, the Clement VII of the Avignon line, and that kings and kingdoms adhered some to one pope and some to the other (Knighton, Chronicle vol. 2, p. 129).

Each line continued. Asked by the king of France for a remedy, the University of Paris proposed three: that both claimants resign, that they accept arbitration, or that a general council decide (University of Paris, On Ending the Schism). In 1409 the cardinals called a council at Pisa, which declared that their united college had the right to summon it and cited both claimants to hear its judgment (Council of Pisa (1409)). The modern editor of the decrees of Constance says that Pisa elected Alexander V as a third pope (Council of Constance, editor’s introduction); his successor John XXIII names him as his predecessor (Council of Constance, session 1). Neither of the older claimants gave way, so that the Council of Constance had three to deal with: John XXIII, Gregory XII of the Roman line and Benedict XIII of the Avignon line (Council of Constance, session 12).

Constance, summoned by John XXIII, deposed him on 29 May 1415 after he had fled the city (Council of Constance, session 12). On 4 July it accepted the resignation of Gregory XII, made through his proxy Carlo Malatesta, having first allowed itself to be convoked afresh in Gregory’s name (Council of Constance, session 14). On 26 July 1417 it deposed Benedict XIII (Council of Constance, session 37). On 11 November Cardinal Oddo Colonna was elected and took the name Martin V (Council of Constance, session 41 (editor’s summary)).

The schism was ended by a council that had judged popes. What that implied for the authority of councils and popes is taken up in the Council of Constance and the Burning of Jan Hus.