ORB Online Encyclopedia--Late Roman Army
Late Antiquity in the Mediterranean. The birth of the Late Roman Army is usually taken to be the reforms of Diocletian (284-305) and Constantine (305-337). Their reforms were not completely innovative and forerunners of all their changes can be seen in the institutions and practices of the army of the third century AD. From the early fourth century, the army was a remarkably stable institution with few changes in practice or structure, suggesting that contemporaries were satisfied with its effectiveness.