What religion had huge power in Western Europe during the Middle Ages?

The story behind the answer

The Latin Church dominated Western Europe’s politics, culture, and daily life. It owned vast lands, collected tithes, ran courts under canon law, and could pressure rulers through tools like excommunication and interdict. Monasteries and cathedral chapters formed dense networks that preserved texts, administered charity, and advised kings, giving clerics outsized influence over governance and education.

Context: The papacy’s claims in the Investiture Controversy, the organization of the Crusades, and the spread of Gothic cathedrals show its reach. Sacraments marked life from baptism to burial, feast days set the calendar, and pilgrimages tied regions together. The 1054 split with the Eastern Church defined a distinct Western identity, while other faiths existed on the margins—seen in Muslim-ruled Iberia and Jewish communities—yet lacked comparable institutional power in the Latin West.