Dagisthaeus put Petra under siege, but, according to the contemporary historian Procopius, acted in an incompetent manner.
Dagisthaeus failed in his task, however, and had to flee before a relieving Sassanid army towards the Phasis river, without giving orders to his men.
After that, Dagisthaeus, joined by the Lazi under King Gubazes, was able to defeat two Persian field armies in Lazica, one under the command of Phabrizus on the Phasis and the other under Chorianes near the river Hippis.
Nevertheless, the Lazi held Dagisthaeus responsible for his failure at Petra and denounced him before Justinian, who had him placed in detention and replaced with Bessas in 549.
He was one of the commanders of the right flank of the Roman army at the battle of Busta Gallorum against the Ostrogoths of Totila and later played a decisive role in the reconquest of Rome.