Charles succeeded to the Frankish throne in 768, and soon was the undisputed king. He led around sixty military campaigns, defeating the Saxons, the Avars, the Muslims and the Basques. He protected the Popes against the threat of the Lombards. He united the kingdom of the Franks with lands never before part of that realm, so that in time the empire of Charlemagne stretched from the Atlantic into Eastern Europe, and from the Baltic Sea to the Mediterranean.
He chose advisers based upon skill and from among all the peoples under him-- not just Franks. He codified the laws and made certain Christian principles common among all the tribes. He suppressed paganism in the lands where it was formerly practiced.
Charlemagne assisted at daily Mass and Vespers, and sought to promote learning and culture. He caused a school to be established at his palace at Aachen. It preserved and taught Latin, philosophy, sciences-- all of the things that could be preserved from Rome.
Moczar writes: "Now there was, for the first time since the fall of Rome, a coordinated, empire-wide onslaught on ignorance, an organized campaign to recover the wisdom of the past and teach its nearly lost skills. The palace school taught both boys and girls, and elementary schools (also teaching both sexes, it seems) were set up all over the king's lands. Above all, Charles was mindful of his responsibilities for the spiritual welfare of his people, and he cared intensely about the religious instruction they were given." p. 60.
Carolingian Miniscule reformed the way letters and words were formed and formatted, and made reading much easier. Things we take for granted, like capital and lowercase letters, and spaces between words, were innovations from Charlemagne's time.
As Charlemagne's kingdom came to compass more or less the old boundaries of the Roman Empire in Europe (minus Spain) his advisers and the Pope agreed that he truly ruled an Empire. On Christmas Day in 800, Charlemagne was crowned Holy Roman Emperor by Pope Leo III in St. Peter's. Moczar notes:
"And so Western Christendom began to take definite shape, its peoples all part of a great Christian commonwealth. Its center was no longer the Mediterranean but the North of Europe, far from the reach of the Muslim raids that threatened even Rome. Its great waterway would be the Atlantic. The concept of the Catholic monarch as defender of the Church and promoter of Christianity, the idea of morally responsible kingship, the cooperation of Church and State, each in its own sphere, were all part of the new Catholic world that had come into being under Charlemagne." p. 62.
Western Civilization as we know it came from three bases: Christianity, Classical culture, and the traditions of the peoples of Europe. We have known them intimately for so long that we do not realize that they needn't have come together at all. Charlemagne was a major reason they did. The union of these three sources of civilization was so strong that it catapulted the West into its glory, a glory that is only now seriously threatened.
Dr. Moczar's book can be found here.