My real name was charles the great. i ruled the frankish kingdom and was six feet four inches tall. i built an empire greater than any known since ancient rome. i fought muslims in spain and tribes from other germanic kingdoms. i spread christianity. i reunited western europe for the first time since the roman empire and my empire was larger than the byzantine empire. i had become the most powerful king in western europe by 800. one of my greatest achievements was the encouragement of learning. who am i?