The Administration of the Empire

Abstract

The expansion of the former city state of Rome into the Roman empire, successfully begun by the middle and late republic, was completed by the Principate. Under the constant pressure of the barbarian incursions, boundaries were unstable in the North (Germania and the Danube basin) and the Asiatic East where the inconclusive seesaw struggle with the Parthians and later with the neo-Persian state created fluctuations. But under Hadrian and the Antonines the Roman empire reached its largest expansion. At its territorial peak Rome and Italy proper were the core.¹ Provinces in the Romanized West were: Spain (three administrative districts); Gallia (Gaul) (six subdivisions); Britannia (England) (three subdivisions), protected to the North against the unconquered Caledonians by a defensive fortification wall (limes) (from the Tyne to the Solway), moved northwards by Antoninus Pius to a line from the Firth of Forth to the Clyde; on the continent the overextended boundary to the North had been wisely taken back in the early Principate from the Elbe to the Rhine River. Successive emperors from Domitian onwards had established another defensive fortified wall stretching from the middle Rhine (Andernach) to the upper Danube (Kelheim) that protected the land triangle (decumates) against the restless neighboring tribes. Securely under Roman control in the room between the Danube and the Alps were the provinces of Rhaetia, Noricum and Pannonia. Farther to the East, the Roman territory embraced the provinces of Moesia and, in the lower Danube basin, the two Dacias acquired by Trajan. All of what today is called the Balkans was Rome’s: Greece proper and the provinces of Thracia; Thessalia; Macedonia; Epirus; and the Illyricum adjoining the Adriatic sea.