In the Roman Catholic Church, the Council of Constance is the 16th ecumenical council. It was held from 1414 to 1418. The council resolved the Western Schism, in which three men simultaneously claimed to be pope. Furthermore, Jan Hus was condemned and executed during the council. In response to a controversy in Poland, the council ruled on issues of national sovereignty, the rights of pagans, and just war. The council represented a high point for the movement that promoted the authority of councils over the authority of the pope, but in the end the pope's authority was re-affirmed.
The council was called by the German King Sigismund (later Holy Roman Emperor), a supporter of Antipope John XXIII, the pope recently elected at Pisa. The council was held from November 16, 1414 to April 22, 1418 in Constance (nowadays Konstanz). Its main purpose was to end the Papal schism which had resulted from the Avignon Papacy. The Council of Constance marked the high point of the Conciliar movement to reform the Church. According to Joseph McCabe, the council was attended by roughly 29 cardinals, 100 "learned doctors of law and divinity," 134 abbots, 183 bishops and archbishops.
The Catholic Church only regards as valid and ecumenical those sessions of the Council that were held after the confirmation of the Council by Pope Gregory XII. The previous sessions, held under the authority of Emperor Sigismund and Antipope John XXIII are not considered valid, and its decrees (including the famous decree Haec Sancta, on Conciliarism), are regarded by the Catholic Church as null and void.
At the time the council was called, there were three popes, all of whom claimed legitimacy. A few years earlier, in one of the first blows to the Conciliar movement, the bishops at the Council of Pisa had deposed both of the two claimant popes and elected a third pope, claiming that in such a situation, a council of bishops had greater authority than just one bishop, even if he were the bishop of Rome. This had only furthered the schism.
An innovation at the Council was that instead of voting as individuals, the bishops voted in national blocs, explicitly confirming the national pressures that had fueled the schism since 1378.
Thus, what historians describe as "the Council of Constance" were, in fact, two different assemblies in the eyes of the Catholic Church and its canon law. The first part is regarded as an illicit assembly, incapable of issuing any valid decree. The second part is regarded as a true Ecumenical Council. The Bishops that were already assembled in Constance accepted to be re-summoned by the authority of Gregory XII since it was known that Gregory XII was willing to resign, so as to allow the election of another Pope, that could be accepted by the whole of Christendom.
With the support of Sigismund, Holy Roman Emperor, enthroned before the high altar of the cathedral of Constance, the Council of Constance recommended that all three popes abdicate, and that another be chosen. In part because of the constant presence of the emperor, other rulers demanded that they have a say in who would be pope. Much of the Council's time was therefore occupied with trying to placate secular rulers rather than in actual reform of the Church and its hierarchy.
Gregory XII then sent representatives to Constance, whom he granted full powers to summon, open and preside over an Ecumenical Council; he also empowered them to present his resignation to the Papacy. This would pave the way for the end of the Western Schism.
The legates were received by Emperor Sigismund and by the assembled Bishops, and the Emperor yielded the presidency of the proceedings to the papal legates, Cardinal Dominici of Ragusa and Prince Charles of Malatesta. On 4 July, 1415 the Bull of Gregory XII which appointed Malatesta and Cardinal Dominici of Ragusa as his proxies at the council was formally read before the assembled Bishops. The cardinal then read a decree of Gregory XII which convoked the council and authorized its succeeding acts. Thereupon, the Bishops voted to accept the summons. Prince Malatesta immediately informed the Council that he was empowered by a commission from Pope Gregory XII to resign the Papal Throne on the Pontiff's behalf. He asked the Council whether they would prefer to receive the abdication at that point or at a later date. The Bishops voted to receive the Papal abdication immediately. Thereupon the commission by Gregory XII authorizing his proxy to resign the Papacy on his behalf was read and Malatesta, acting in the name of Gregory XII, pronounced the resignation of the papacy by Gregory XII and handed a written copy of the resignation to the assembly.
Former Pope Gregory XII was then created titular Cardinal Bishop of Porto and Santa Ruffina by the Council, with rank immediately below the Pope (which made him the highest ranking person in the Church, since, due to his abdication, the See of Peter was vacant). Gregory XII's cardinals were accepted as true cardinals by the Council, but the members of the council delayed electing a new pope for fear that a new pope would restrict further discussion of pressing issues in the Church.
By the time the anti-popes were all deposed and the new Pope, Martin V, was elected, two years had passed since Gregory XII's abdication, and Gregory was already dead.
A second goal of the council was to continue the reforms begun at the Council of Pisa. These reforms were largely directed against John Wycliff, mentioned in the opening session, and condemned in the eighth, May 4, 1415 and Jan Hus, and their followers. Jan Hus, summoned to Constance under a letter of indemnity, was condemned by council and burned at the stake notwithstanding on July 6, 1415.
The council also attempted to direct ecclesiastical reforms. However, once two anti-popes, Baldassare Cossa (John XXIII), who fled from Constance on March 20, 1415, and Peter de Luna (Benedict XIII) had been eliminated, Gregory XII, the successor of the Roman line, was induced to resign. The council with great care to protect the legitimacy of the succession, ratified all his acts and a new pontiff was chosen. The new pope, Martin V, elected November 1417, soon asserted the absolute authority of the papal office, and the claim that a council might be superior to a single pope was set aside when it was later declared that a council of Bishops has no greater authority than the Pope.
During the proceedings of the Council, John of Falkenberg accused Poles of being: “guilty of the abominable crime of using Pagan allies in their war against the German Order.” He proposed that “the Poles must be exterminated.” In his Liber de doctrina, Falkenberg argued that “the Emperor has the right to slay even peaceful infidels simply because they are pagans; the Poles too should be killed for allying themselves with the infidels and resisting Christian Knights. The Poles deserve death for defending infidels, and should be exterminated even more than the infidels; they should be deprived of their sovereignty and reduced to slavery.”
In his Papal Bull of January 10, 1424, Pope Martin V “wanting to obviate the evils that may come to Poland from the errors and opinions advocated by Falkenberg…Imposed the penalty of excommunication ipso facto on all Christians whoever they might be…who might dare to propagate, defend, assert, etc. the condemned errors.”