 When King Grimoald went south to rescue his son Romuald and the Duchy of Benevento from the invasion of the Byzantine Emperor Constans II, he put Lupus in charge of Pavia.Lupus played the tyrant during Grimoald's absence, believing that the king would not return, thus was forced to flee to Cividale, seat of Friuli, and enter into rebellion when the king did come north again.Grimoald promptly asked the Khagan of the Avars to attack Friuli in order to prevent a civil war in Italy.