Which 1378–1417 crisis featured rival popes and competing obediences in Western Europe?

It refers to the 1378–1417 papal crisis in which rival claimants in Rome and Avignon—and after 1409 even a third from Pisa—fought for legitimacy, dividing Christendom into competing “obediences.” The deadlock ended at the Council of Constance (1414–1418), which deposed or accepted the resignation of the contenders and elected Martin V, restoring a single recognized pope. The turmoil grew out of the Avignon Papacy and a split among French and Italian cardinals. European kingdoms took sides—France, Scotland, and Castile backing Avignon; England and much of the Holy Roman Empire backing Rome—turning church politics into high diplomacy. The crisis weakened papal prestige and energized conciliarism, the idea that general councils could supersede popes, influencing reform movements from the Hussites to currents that later fed the Reformation.