Charlemagne

   His coronation as emperor by Pope Leo III (qq.v.) at Rome (q.v.) on 25 December 800 provoked a major crisis with Byzantium (q.v.). There could be only one emperor; this everyone agreed upon. Thus, in Byzantine eyes Charlemagne was a usurper. In western eyes, he appeared differently. In 800 Irene (q.v.) sat on the throne of Byzantium, in contradiction to previous tradition that a woman could not hold sole imperial power. In effect, it could be argued that the throne was theoretically vacant. Moreover, Irene had come to power by blinding her son, Constantine VI (q.v.). Irene's support of icon (q.v.) veneration was attacked in the Libri Carolini (Books of Charles), issued ca. 793 by Charles's advisors to attack the Council of Nicaea (q.v.) of 787. Despite these justifications, Charlemagne attempted to improve his position by proposing marriage to Irene, but Irene was overthrown and exiled in 802 by Nikephoros I (q.v.). Years of negotiations followed, until in 812 Charlemagne was granted the imperial title, though the Byzantines considered him emperor of the Franks (q.v.), not emperor of the Romans.