Charlemagne

Charlemagne was the third leader of the Carolingian dynasty (751-987 A.D., ruling the Franks)—and the most important (as well as famous) one by far. He was a Christian and did much to expand both his kingdom and Christianity. He promoted education, starting palace schools, and attempted to reestablish the Roman Empire, though without success. His fault lay in the way he persecuted non-Christians. His most important contribution was definitely the way he spread Christianity.