How did Diocletian contribute Rome?

Answer 1

Diocletian created the tetrarchy (rule by four) and subdivided the Empire into four main administrative units, the praetorian prefectures. He appointed fellow general Maximian as co-emperor in 285. Maximian took overall control of the western part of the empire, while Diocletian took overall control of the eastern part. Then these two men became senior emperors (Augusti) with the creation, in 293, of two junior emperors (Caesars) who were subordinates of the Augusti. The Caesars Constantius and Galerius.. One of the tasks of the Caesars was to defend the troubled frontiers along the rivers Rhine and Danube respectively, which had been under constant attack from outside the empire.

Each of the four emperors headed one of the four praetorian prefectures. Galliae (Gaul, Britannia and Hispania), was headed by Constantius; Italia et Africa (Italy, Switzerland and north-western Africa) was headed by Maximian; Illyricum (the Balkan Peninsula except for Thracia, in modern eastern Bulgaria) was headed by Galerius; and Oriens (Thracia, the Roman territories in Asia, Egypt and eastern Libya) was headed by Diocletian. Galliae and Italia et Africa were in the west. Illyricum and Oriens were in the east. These were administrative subdivisions. Diocletian stressed that the four praetorian prefectures were administrative units and that the empire was indivisible.

Diocletian also created imperial seats, one for each emperor: Milan (in northern Italy, for Italia et Africa) Nicomedia (in north-western Turkey, for Oriens) Augusta Trevorum (Triers in Germany near the river Rhine, for Galliae) and Sirmium (near Belgrade on the river Danube, for Illyricum).

This reform had several aims:

1) The bad experience of recent sole emperors suggested to Diocletian that sole emperors were vulnerable and that co-emperorship made power more secure.

2) Diocletian could not create an informal co-emperorship with a son as previous emperors had done because he was hairless; he had a daughter and no sons. Therefore, he needed a trusted co-ruler from outside the family and had to create a formal co-emperorship

3) There was a need to improve imperial control over the empire. There had been conflict between powerful men many provinces of the empire and also attempts at usurpation in some areas. Diocletian shared controlling the provinces with three men.

4) There was also a need to improve the efficiency of the defence of the vast frontiers of the empire. He entrusted the defence of the most troubled tracts of the frontiers to the Caesars.

The tetrarchy begun to unravel after Diocletian and Maximian abdicated in 305 and eventually fell as the emperor started to fight each other over power and Constantine the Great emerged as sole emperor in 327.