The greatest of the Frankish rulers, Charlemagne brought a new ideal of kingship to Europe that had a tremendous influence long after his own empire crumbled. The kingdom of the Franks was one of the most powerful of the barbarian kingdoms of the Dark Ages. Founded after the fall of the Roman Empire, it included much of modern-day France, Germany, and the Netherlands, along with all of Belgium and Switzerland. Shortly before his death in 768 AD, Pepin the Short divided his kingdom between his sons Charles and Carloman. However, Carloman died only three years afterward and left Charles as sole king of the Franks.
Charles was both an ambitious ruler and an effective one and within his own lifetime, he became known as Charles the Great, a title also rendered as Carolus Magnus and the more familiar Charlemagne. Charlemagne perceived himself as being the heir to both the ancient kings of Troy and the great Roman emperors, claiming actual descent from the former and reviving the ideals and administrative principles of the latter. Additionally, Charlemagne embarked on an extensive campaign of military activity and expanded the Frankish kingdom to include Bavaria, Lombardy, Corsica, and Saxony, and virtually doubled the amount of territory controlled by the Franks to include most of Europe.
Yet, Charlemagne was more than simply a warrior-king. Although he was himself illiterate, Charlemagne had a fine appreciation for learning and surrounded himself with scholars at his court at Aachen. At the palace school, the scribes were responsible for preserving a great amount of Latin literature. Furthermore, Charlemagne cultivated diplomatic relations with many important figures. This was particularly true of the Pope Hadrian I and Charlemagne made several important pilgrimages to Rome to foster harmonious relations with the papacy. On Christmas day of 800 AD, Pope Hadrian I crowned Charlemagne emperor of what would later be called the Holy Roman Empire. Nonetheless, Charlemagne's extensive empire did not last long. After his death it was divided among the heirs of his son Louis the Pious. This was first done at the Treaty of Verdun in 843 AD, and again in 855 AD.
Perhaps Charlemagne's most lasting contribution to European society was his idea that a king should rule over both the state and the church. Charlemagne saw it as his right and duty to administer divine law over all Christians and to maintain authority over the workings of the Church. This conception of rulership, though surviving in the Byzantine Empire, had not been seen in Europe since the fall of the Western Roman Empire. By entwining the spheres of power and influence of the empire and the papacy, Charlemagne sowed the seeds for a power struggle between these two institutions which would last throughout the Middle Ages.