Palmyrene Empire
After these episodes, the records of the "Fulminata" are scarce. The Palmyrene Empire was reconquered by Aurelian; Emperor Diocletian defeated the Sassanids and moved the frontier to Northern Mesopotamia. The Twelfth, which probably took part to these campaigns, is recorded guarding the frontier of the Euphrates in Melitene, at the beginning of the 5th century ("Notitia Dignitatum").