Chilperic I, king at Paris, and the Burgundian king Guntram, sought an alliance with Childebert, who was adopted by both in turn. Because Guntram was lord of half of Marseille, the district of Provence became a centre of a brief dispute between the two.
Guntram allied with Dynamius of Provence, who instigated the canons of the Diocese of Uzès to elect their deacon Marcellus, son of the senator Felix, as bishop in opposition to their already-elected bishop Jovinus, a former governor of Provence. While Jovinus and Theodore, Bishop of Marseille, were travelling to the court of Childebert, Guntram had them arrested. Dynamius, meanwhile, blocked Gundulf, a duke of an important senatorial family and Childebert's former domesticus, from entering Marseille on behalf of Childebert. Eventually he was forced to yield, though he later arrested Theodore again and had him sent to Guntram. Childebert replaced him in Provence by Nicetius (585). Despite his revolt, Childebert formally restored Dynamius to favour on 28 November 587.
On the death of Guntram in 592, Childebert annexed the kingdom of Burgundy, and even contemplated seizing Clotaire's estates and becoming sole king of the Franks. He died, however, in 595. Childebert II had had relations with the Byzantine Empire, and fought on several occasions in the name of the Emperor Maurice, against the Lombards in Italy, with limited success.