What were some of Charlemagne's contributions?

Also referred to as Charles the Great, Charlemagne is considered the first Holy Roman Emperor, and some of his accomplishments included the eliminating the Avar Empire and removing Duke Tassilo from Bavaria. Charlemagne also assisted Pope Adrian I, by seizing Pavia to prevent the Lombard king from pressuring him to anoint his sons as Frankish kings.

Charlemagne was the illegitimate child of Pippin III and Bertrada. He was married five times and kept a variety of concubines. In spite of this, he was said to be a family man with many children, and he always took his sons with him when he went on campaigns.