Gallus arrives to Poetovio in Pannonia, and Barbatio, an officer who had been supporting Gallus' dismissal within Constantius' court, surrounds the palace of the caesar and arrests him, stripping Gallus of the imperial robes, but assuring him that no harm will come to him.

Theodomir had two "brothers"—actually, brothers-in-law—named Valamir and Videmir, with whom he had ruled jointly as a vassal of the late Attila the Hun.

Theodemir is Arian, while his wife Erelieva is Catholic and had taken the Roman Christian name Eusabic upon her baptism.

Erelieva has borne him two children: Theoderic (454–526) and Amalafrida.

Theodomir takes over the three Pannonian Goth reigns after the death of Videmir in 470, having earlier inherited the heirless Valamir's part of the kingdom on the latter’s death in 465.