According to Theophanes, Mundus was the son of Γιέσμ, a ruler of the East Germanic tribeGepids, and nephew to another Gepid ruler, Trapstila. Giesmus name root *gesm <*gésəm derives from Turkic-Mongolian root kes/käs. His father was killed in battle against the Ostrogoths of Theoderic in 488, after which Mundus accepted the latter's invitation to join him. He remained in Italy until Theodoric's death in 526, at which point he returned to his homeland. The exact date of Mundus's birth is unknown. According to Jordanes, Theophanes and John Malalas, Mundus had Hunnic Attilanic descent. His name has same etymology like Attila's father Mundzuk, from Turkic*munʒu.
In Roman service
In 529, Mundus sent envoys to Justinian, offering his allegiance. His offer was accepted, and Mundo was appointed magister militum per Illyricum, head of all military forces in Illyria and along the Danubian frontier. During the next two years, he defeated incursions of Slavs and Bulgars into the Balkans and sent much booty to Constantinople. In 531, Mundus was briefly magister militum per Orientem, replacing Belisarius after his failure at Callinicum, but it seems that Mundus never actually traveled to the East to assume that command. In January 532, he was again appointed commander of the Illyrian forces. In the same month, he happened to be in Constantinople with a force of Heruli mercenaries when the Nika riots broke out. Mundus remained loyal to Justinian and, along with Belisarius, was responsible for the massacre of the supporters of Hypatius in the Hippodrome and thus the reassertion of imperial control. Mundus remained in command of the forces in Illyricum thereafter. In 535, as Justinian launched his attempt to reconquer Italy from the Goths, he led his forces into Dalmatia, which the Goths held, while Belisarius invaded Italy by sea. Mundus defeated the Goths and took the capital, Salona; but, early in the next year, a new Gothic army arrived to reclaim the province. In a skirmish near Salona, Mundus's son Mauricius was trapped with only a few men by a larger Gothic force and was killed. Enraged by the loss of his son, Mundus sallied out and defeated the Goths but was mortally wounded in the pursuit.
