History of the papacy (1048–1257)
Henry IV's Walk to Canossa in 1077 to meet Pope Gregory VII (1073–85), although not dispositive within the context of the larger dispute, has become legendary.
Large parts of northern and central Italy became a constituent kingdom of the Holy Roman Empire in 962, from which point emperors were Germanic.
The first seven Ecumenical Councils had been attended by both Western and Eastern prelates, but growing doctrinal, theological, linguistic, political, and geographic differences finally resulted in mutual denunciations and excommunications.
Pope Nicholas II promulgated In Nomine Domini in 1059, which limited suffrage in papal elections to the College of Cardinals.
It began as a dispute in the 11th century between the Holy Roman Emperor Henry IV, and the Gregorian Papacy concerning who would control appointments of church officials (investiture).
The popes fought to free the appointment of bishops, abbots and other prelates from the power of secular lords and monarchs into which it had fallen.
Henry IV was ultimately driven by a revolt among the German nobles to make peace with the pope and appeared before Gregory in January 1077 at Canossa.
Dressed as a penitent, the emperor is said to have stood barefoot in the snow for three days and begged forgiveness until, in Gregory's words: "We loosed the chain of the anathema and at length received him into the favor of communion and into the lap of the Holy Mother Church".
[1] Pope Nicholas II, elected in 1058, initiated a process of reform which exposed the underlying tension between empire and papacy.
The primary causes of the Schism were disputes over papal authority— the pope claimed he held authority over the four Eastern Greek-speaking patriarchs, and over the insertion of the filioque clause into the Nicene Creed by the Western Church.
Not only could it restore Christian control over the Holy Land, but it also provided a means of domestic pacification that focused the aggression of the European nobility towards the Muslims instead of each other.
Pope Urban II asked the Frenchmen to turn their swords in favor of God's service, and the assembly replied "Dieu le veult!"
