The Council That Ended Three Popes

When the council opened at Constance in November 1414 there were three men claiming the papacy: a Roman line, an Avignon line, and a third elected at Pisa in 1409 by a council that had tried to end the schism and had merely added to it. The gathering at Constance was summoned by the Pisan claimant under pressure from the emperor Sigismund, and it disposed of all three. John XXIII fled the city in disguise and was deposed; Gregory XII was allowed to convoke the council formally and then resign, a device that preserved the legitimacy of the Roman line; Benedict XIII refused to go, was deposed, and was abandoned by his remaining supporters.

In November 1417 the council elected Martin V, and a schism that had run for thirty nine years was over. To justify what it had done the council issued the decree Haec sancta, declaring that a general council holds its authority immediately from Christ and that everyone including the pope is bound to obey it in matters of faith and of reform, and the decree Frequens, requiring councils to meet at fixed intervals thereafter. Those two texts are the high point of conciliarism, and the papacy spent the following century dismantling the claim they made. Voting was by nation rather than by head, which prevented the large Italian contingent from carrying every question.