Why was Charlemagne not happy to be crowned by the pope?

Charlemagne was initially displeased with being crowned by the pope because he believed that his authority as a ruler should be derived from his own merits and achievements, not from a religious figure. He felt that the act implied a certain subservience to the Church and suggested that his power was granted by the pope rather than being inherent to his position as emperor. Additionally, he was concerned about the potential for the pope to wield influence over political matters, which could undermine his sovereignty.