How did the papacy assert power over European monarchs?

The papacy asserted power over European monarchs through excommunication, interdicts, and control over the appointment of bishops.

The papacy, as the highest authority in the Catholic Church, wielded significant power over European monarchs during the Middle Ages. This power was asserted in several ways, one of which was through the threat or actual use of excommunication. Excommunication was a severe punishment that excluded a person from the community of believers, effectively cutting them off from the Church and its sacraments. This was a powerful tool as it not only had spiritual implications, but also political ones. A monarch who was excommunicated was seen as unfit to rule, and their subjects were released from their oaths of allegiance. This could lead to rebellion and instability, making excommunication a potent weapon in the hands of the Pope.

Another way the papacy asserted power was through the use of interdicts. An interdict was a censure that could be placed on an entire country, prohibiting the performance of certain sacraments and religious ceremonies. This was a collective punishment that affected all the subjects of a monarch, not just the ruler themselves. The threat of an interdict could be used to pressure a monarch into compliance with the Pope's demands.

The papacy also controlled the appointment of bishops, a key element in the power dynamics of the time. Bishops were not only religious leaders, but also important political figures who controlled vast territories and resources. By controlling who became a bishop, the Pope could influence the political landscape of a country. This was particularly true in the Holy Roman Empire, where bishops were among the electors who chose the Emperor.

Finally, the Pope had the power to call for Crusades, military expeditions to the Holy Land. Monarchs who participated in these Crusades could gain prestige and influence, but they also risked the Pope's disapproval if they failed to support the Crusades or if they pursued their own interests at the expense of the Church's goals. This gave the Pope another way to exert influence over European monarchs.