This paper has a assignment to describe relation between Popes (Adrian I and Leo III) and Charles the Great. It will be explored the mutual dependence between Popes and Charles the Great and who had primacy in that relation. Charles was a faithful son of the Church and a reliable ally of the Roman Pope and the papal state. The relation between of Pope Adrian and Charles could be characterized as equal while Charle’s relation with the Pope Leo was commanding. A picture that represents as a man who is devoted to the interests of the Church neglects the fact that he unselfishly used church institutions to establish his secular authority.