"Letter to Gregory VII," January 24, 1076

Published in Select Historical Documents of the Middle Ages, 1910

"First Deposition and Banning of Henry IV," February 22, 1076

Published in Select Historical Documents of the Middle Ages, 1910

"Henry, king not through usurpation but through the holy ordination of God, to Hildebrand [Gregory], at present not pope but false monk."

From "Letter to Gregory VII"

During the early part of the Middle Ages, popes—that is, the spiritual and political leaders of the Catholic Church—enjoyed good relations with kings in Western Europe. This had been the case since the time of Clovis, king of the Franks, and the strong relationship became stronger in 800, when Pope Leo III crowned the Frankish king Charlemagne (SHAHR-luh-main; ruled 768–814) as "Emperor of the Romans."

That title...