Indulf is first mentioned, by the historian Procopius, as a barbarian (in all probability a Goth) bodyguard of the Byzantine general Belisarius.
[2] In late spring/early summer of 549, the Ostrogoth king Totila (r. 541–552) entrusted him with a large army and a fleet, and sent him to campaign in Dalmatia, which the Byzantines had taken in 535/536.
When a Byzantine relief force sailed against them, Indulf and his fellow-general Gibal headed the fleet that confronted them.
The resulting Battle of Sena Gallica was a disaster for the inexperienced Goths; Gibal fell and most of the ships were sunk or captured, but Indulf was able to escape with 11 vessels.
Upon reaching land, the Goths burned their ships, and quickly abandoned the siege of Ancona, taking refuge in Auximum.