The thirteenth century marked the zenith of medieval papal power. Innocent III placed England under interdict, presided over the Fourth Lateran Council, and claimed authority over all Christian rulers. The mendicant orders - Franciscans and Dominicans - renewed religious life, while the great cathedrals and universities testified to the Church's cultural leadership.

Yet crisis followed triumph. The clash between Boniface VIII and Philip IV of France ended in humiliation at Anagni. The popes retreated to Avignon for seventy years, and when they returned to Rome, a disputed election sparked the Western Schism. For nearly forty years, two and then three men claimed to be pope, scandalising the faithful.

The Council of Constance healed the schism and elected Martin V. The Renaissance popes who followed rebuilt Rome, patronised the arts, and prepared for a new age - though their worldliness would soon provoke the Protestant challenge. The medieval Church ended as it had begun: facing both crisis and opportunity.