Reform of Pope Gregory VII

Timeline

1. c. 1050–1073Rome · LazioHildebrand held cardinalate and key administrative posts in the Curia for many years, promoting clerical celibacy and opposing simony, and allied with reform movements such as the Cluniac order, laying institutional and public-opinion groundwork for the later expansion of papal authority.
2. c. 1075Rome · LazioThe Dictatus Papae, in twenty-seven articles, proclaimed principles such as the pope's power to depose monarchs and that bishops be appointed only by the pope, advancing Gregory's reform from moral rectification to a papal constitutional text of universal binding force.
3. 1075–1077Rome · LazioGregory VII issued decrees forbidding secular rulers from investing and consecrating bishops, and successively excommunicated Henry IV, bringing the reform system into direct conflict with imperial investiture tradition and plunging European church-state relations into open crisis.
4. 1077–1080Rome · LazioAfter Henry IV's penance at Canossa won him absolution, the two sides briefly reconciled; by 1080 Gregory again excommunicated Henry and backed a rival king, and under military and diplomatic pressure the reform system still upheld papal final adjudication over investiture.