Leo III is remembered as Charlemagne's pope. The cardinal priest of Santa Susanna, Leo was unanimously elected to the papal see in 795. Four years later, a mob led by relatives of his predecessor, Pope Adrian I, tried to blind Leo and cut out his tongue; such mutilations would have rendered him unfit to rule. Having escaped physical danger, he was imprisoned in a monastery during an attempt to depose him. He escaped to Charlemagne's retreat at Paderborn, where Alcuin defended him against charges of adultery and purjury on the grounds that no earthly power can judge the successor to St. Peter. Leo returned to Rome in 800, and on Christmas day, he crowned Charlemagne Holy Roman Emperor. Leo fought adoptionism in Spain and was circumspect in his judgement of the filioque, the use of which he allowed but which he considered omittable. When Charlemagne died in 814, Leo began to assert his power more directly and personally prosecuted conspirators against him. Still despised by the upper class because of his plebian origin, Leo died in 816.