For 10 points, name this Carolingian king, the son of Pepin the Short.
This ruler discarded his wife, the daughter of Desiderius, in favor of Hildegard. This man established the Palatine School at his residence, headed by the English cleric Alcuin. He defeated the Avars with the help of his son Pepin of Italy, and in response to Pope Hadrian I he entered Italy and subjugated the Lombards. At the Treaty of Verdun, his lands were divided among his descendants Lothaire, Charles the Bald, and Louis the German. One of this man's paladins was killed by Basques at Roncesvaux Pass. Pope Leo III crowned him Holy Roman Emperor in 800. For 10 points, name this Carolingian king, the son of Pepin the Short.
This ruler discarded his wife, the daughter of Desiderius, in favor of Hildegard.
{Charlemagne} [or {Carolus Magnus} or Charles the {Great} or Charles I or {Karl der Grosse}]