What measures were undertaken by Constantine to stabilize the empire?

Answer 1

Constantine I (or the Great, reigned as sole emperor 324-337) retained most of the reforms which Diocletian (reigned 284-305) had introduced to stabilise the empire.

Diocletian more than doubled the number of provinces by subdividing them in order to curtail the power of the governors (who could be potential usurpers) and make tax collection and the enforcement of the law more efficient. He grouped the provinces under sixteen dioceses headed by a vicarious (vicars) as deputies of the four praetorian prefectures (see below) into which the dioceses were, in their turn, grouped. He reduced the role of the governors to that of presiding over the lower courts. The higher courts were now presided over by the vicars. Their military command was taken away from them. Diocletian separated civilian and military power by creating new military commanders, the duces (dukes) which were separate from the civil service (previously the governors also commanded the troops in their provinces). The duces sometimes headed troops in two or three provinces. Tax collection, previously assigned to the procurators (juniors of the governors) was assigned to the governors and to the vicars.

Diocletian also increased the size of the bureaucracy, probably doubling it from 15,000 to 30,000. This was a disproportionately high number given the population of the empire at the time. Half of this was provincial and diocesan officials. The other half was the staff of the praetorian prefects, the imperial court and grain supply officials.

The imperial court was highly structured. It was organised in different departments headed by magistri (ministers). There were legal advisers and two treasurers, one of the public treasuries and one for the imperial estates.

Constantine retained these reforms. The only change he made was the tetrarchy.

Diocletian decided that one man could not rule the vast empire alone because of the murders of previous emperors, because there was tension in nearly all the provinces of the empire and because of raids into the empire at various points of its vast frontiers. Therefore, he created the tetrarchy (rule by four). He appointed his fellow general Maximian as co-emperor. Diocletian took charge of the eastern part of the Roman Empire and Maximian of the western part. He then created two junior emperors (Caesars) as subordinates of Diocletian and Maximian, who became senior emperors (Augusti). He also subdivided the empire into four main administrative units (the praetorian prefectures of Galliae, Italia et Africa, Illyricum and Oriens). Each of them had one of the emperors in charge. This system provided stability during his reign. However, when he retired these men fought each other. Constantine I fought two civil wars, became the sole emperor and restored stability.

Originally, Constantine was one of the junior emperors. The then fought two civil wars; one against a usurper emperor in Italy and one against his senior co-emperor in the east when he became the senior emperor of the western part of the Roman Empire. Thus he became the sole emperor of the whole of the Roman Empire, ending the tetrarchy. However, he retained the four praetorian prefectures and appointed his three sons and a nephew as Caesars in charge of them. Therefore, Constantine created his own version of the tetrarchy, one which was subordinated to himself alone. This system also fell apart as his sons started fighting each other after his death.