THE CHURCH

During this age, the pope held the spiritual authority in the western Christian church. The pope could claim papal supremacy, or authority over all secular rulers. This included the king/emperor. High members of the church usually belonged to the noble class, they were lords. The pope also was the leader of a church army that supervised activities. He also held a lot of land.
Nearly everyone at the time believed that if they didn't believe in God, do good works, and participate in the sacraments, they would go to hell. The church administered the sacraments and could deny it to anyone. This is what gave them their power.
The canon laws influenced many aspects of life including marriage, wills, and morals. If you disobeyed church law you could be excommunicated, excluded from the church. If a noble committed a serious offense against the church, they could face an interdict, this excommunicated an entire town or village.
The church tried to use it's power to end warfare and fighting.