When the Western Roman Church split in 1378, at one point there were three people who claimed to be the rightful pope at the time, which obviously caused some troubles because all of them were relentless in their convictions. Thus the credibility of the pope was brought into question. The reason for it was that the Avignon Papacy was ended, and the seat of the Pope brought back to Rome, which caused two sides (those anti-pope in Avignon and those for a Roman pope) to fight all the time, which affected the Catholic Church as well. All this was settled by the Council of Constance, which started in 1414 and lasted for four years.
