Wikipedia:
In the history of Christianity, the Conciliar movement or “Conciliarism” was a reform movement in the 14th and 15th century Roman Catholic Church which held that final authority in spiritual matters resided with the Roman Church as corporation of Christians, embodied by a general church council, not with the pope. The movement emerged in response to the Avignon papacy— the popes were removed from Rome and subjected to pressures from the kings of France— and the ensuing schism that inspired the summoning of the Council of Pisa (1409), the Council of Constance (1414-1417) and the Council of Basel (1431-1449). The eventual victor in the conflict was the institution of the Papacy, confirmed by the condemnation of conciliarism at the Fifth Lateran Council, 1512-17. The final gesture however, the doctrine of Papal Infallibility, was not promulgated until the First Vatican Council of 1870.
[http://tatumweb.com/blog/2006/01/01/counciliar-movement/
During the Great Schism, when three men simultaneously claimed Divine rights to the papacy, the Holy Roman Emperor assembled a council at Constance in Germany to chose a new Vicar of Christ, Martin V. Upon ascending to the papacy Martin repudiated all acts of the council, except the one by which he ruled. In spite of the legal difficulties this raised, Martin V had good reason to deny the work of the council for it raised a very important question: Who is greater, a general council that creates the pope, or the pope who claims supremacy over councils? The conciliar movement aimed at transforming the papacy into something like a limited monarchy. Constance solemnly decreed that general councils were superior to popes and that they should meet at regular intervals in the future. The pope called this heretical. His return to power plus the inability of later councils to introduce much-needed reforms enabled the popes, by 1450, to discredit the concilior movement.
