The son of Sigebert III, Dagobert was packed off to an Irish monastery following the death of his father in 656, and the Austrasian throne was taken by Childebert the Adopted, son of Grimoald, the Austrasian mayor of the palace. After the downfall of Grimoald and Childebert, Dagobert's cousin Chlotar III, king of Neustria, secured the Austrasian throne (662) for Childeric II. On Childeric's assassination in 675, Dagobert was traced, with effective assistance from Wilfrid, bishop of York, and restored to the throne in 676. His murder three years after he took the throne led to the nominal unity of all the Frankish lands under Theodoric III.