Theodimundus was the son of strategos (and likely MVM vacans)[1] Mauricius, a son of magister militum Mundus, himself a possible descendant of Attila the Hun.
[2][3][4] He belonged to the barbarian military aristocracy fighting for the Byzantines in the Balkans.
[5] Theodimundus was active during the reign of Emperor Justinian (r. 527–565).
As a young man (by 540/541), he served in the Byzantine army during the Gothic War of 535-554 under Vitalius.
He participated in the Battle of Treviso against the Gothic king Hildebad and barely escaped with his life, fleeing with his commander after the Byzantine defeat.