Initially, reforming popes were supported by German kings/emperors. However, they also began to elaborate an ideology that insisted that churchmen (and popes) should not just be autonomous from secular powers– they should be able to overrule secular powers.

This came to a head under Gregory VII. To some extent, Gregory VII represented more grass-roots, local, Italian reformers, although he had also travelled in East Francia. He also developed much of his reforming agenda without having to compromise with a strong emperor.

In 1056, Henry IV had become king while still a child. His advisors struggled to control the kingdoms of Germany and Italy as his ancestors had done. Italian nobles therefore looked to the strong, reforming popes for leadership. In particular, the powerful and wealthy Matilda-- the noble who ruled Tuscany-- supported Gregory VII. Matilda was particularly important because her power base in Tuscany was located in the north of Italy, controlling the routes between Italy and the rest of Europe.

Image above: Gregory VII and Matilda of Tuscany talk while a much smaller king looks on, as portrayed in a manuscript made c. 1115 (Cod. Vat. lat. 4922, f. 49r)

The Investiture Contest

Eventually, Henry tried to reassert his power relative to the pope, leading to an extensive conflict.

The spark that triggered overt conflict between the pope and king/emperor was the issue of who got to appoint bishops, archbishops, etc.

Investiture = process and ceremony of appointing a bishop or archbishop

Both Henry and Gregory wanted to install an ally as archbishop as archbishop of Milan, a powerful city in Northern Italy (which had its own reforming movement in the pataria). Gregory had even urged nobles and churchmen not to respect bishops and abbots who had been appointed by secular figures.

Gregory excommunicated Henry and all (German) bishops who supported him and called on the nobility to revolt against Henry.

Read This Read Henry IV's letter to Gregory VII and Gregory VII's letter to Hermann of Metz (in Rosenwein's Reading the Middle Ages, no. 5.4 and 5.5)

Henry and Gregory reconciled but then quarreled again. Count Rudolf of Rheinfelden, with Gregory’s support, declared himself (anti-)king in 1077, creating a civil war. Meanwhile, Henry called synods of German and north Italian clerics and had (anti-)pope Clement III elected and invaded Italy.

Penance as Performance Art?

In 1077, with Henry’s troops approaching, Gregory fled to Matilda’s castle at Canossa. Henry, however, approached Canossa barefoot and penitent. He reportedly waited on his knees for three days during a blizzard.

Optional: you can see a dramatization of two competing chronicle accounts in the video below. The voice over is in German, but the visuals are the important thing. The relevant clip begins at 30:50 and ends at 35:00.