During Babylonian Captivity, many of the Popes tended to reside in Avignon rather than Rome. After a new Pope, Urban VI, is elected, backlash causes the Cardinals to elect Pope Clement VII. Urban VI moves back to Rome and claims himself to be the true Pope, causing Europe to become split over which Pope they support (their decisions were usually influenced by politics). The Council of Pisa tries to resolve this, but ends up adding a new Pope. Heretics call out the illegitimacy of the Church during this time, until the Council of Constance revolves the Schism by electing a new official Pope (Pope Martin V), executes heretics, and attempts to long-term reform the Church (but they were dissolved before they could).