What was Charlemagne's relationship with the Saxons?

Charlemagne had a tumultuous relationship with the Saxons, as they resisted his efforts to Christianize them and integrate them into his empire. The conflict culminated in the thirty-year Saxon Wars, during which Charlemagne used military force to subdue and convert the Saxons to Christianity. After their defeat, the Saxons eventually became part of Charlemagne's Frankish Empire.