Pope Gregory VII became Pope in the year 1073. Immediately, he issued a set of rules for leaders and other people to follow. He declared supremacy over everyone else, he declared that only himself could appoint leaders, and he had the power to remove emperors from the throne. Some people did not like this.
I think that I should be able rule over everyone, remove emperors, and appoint bishops.
One person that disagreed with the Pope was Henry IV. He thought that this was against his own power and rights as an emperor. He decided that it was best for him to disobey the Pope's rules.
Just because Gregory is the new Pope, does not meant that he can take way my rights as an emperor and make me less powerful!
The first thing that Henry IV did to disobey the Pope's new laws was to appoint a new bishop for Milan, Italy. Pope responded by appointing a rival bishop. To counter the Pope, Henry tried to remove the Pope.
Too defy this Pope, I think I should appoint a bishop in Milan. If he does something to me, I will just try to remove.
After learning about how Henry attempted to remove him from the Pope position, Pope Gregory VII excommunicated Henry to retaliate. He also freed Henry's subjects from their feudal oaths of loyalty. Across Europe, clergy and secular members chose sides in this epic clash.
Because of his attempts to remove me from office, I shall excommunicate Henry IV!
To end his excommunication, Henry stood outside Pope Gregory's castle for 3 days and nights. When teh Pope would finally see him, he lifted Henry's excommunication and the Pope also forgave him. Even though the Pope lifted the excommunication, Hnery still took revenge by marching his army to the Pope's castle and forced him from office.
I shall stay out here until the Pope sees me and lifts my excommunication. Then, I will take my revenge on him for ever excommunicating me in the first place.
Even many years after Pope Gregory VII and Henry IV died, popes and emperors clashed against each other. This all ended in 1122, when an agreement was reached called the Concordant of Worms. This agreement gave the Pope the sole responsibility of appointing bishops, but emperors could grant fiefs to them to win the bishops' loyalty.
I think we should make an agreement. What should it be called?
I think it should be called the Concordant of Worms.