Royal Frankish Annals
Liutperga played an apparently major role in her husband's opposition to Charlemagne. Frankish annals references to Liutperga suggest this. The Annales Mettense Pirores refer to her as Tassilo's "wicked wife" and the Revised Royal Frankish Annals refer to the Liutperga's "urging" of her husband to push the Avars into conflict with Charlemagne.