Diocletian's Reforms — The Dominate and the Tetrarchy
Diocletian took the throne in 284 after fifty years of chaos and reorganised the empire so thoroughly that it lasted another two centuries. He was a Dalmatian soldier of obscure family, and the problem he inherited was structural rather than military: an empire too large for one man to defend, in which any general with an army could be proclaimed and usually was. His answer was to divide the job. He appointed a colleague as co-emperor in 286, and in 293 added two junior emperors, producing the tetrarchy — four rulers with four capitals, four field armies, and a scheme of succession by promotion rather than by birth. The provinces were subdivided from about fifty to over a hundred and grouped into dioceses, civil and military commands were separated so that no governor had troops, and the army was enlarged and divided into frontier garrisons and mobile field forces. The taxation was rebuilt on a census of land and labour reassessed every fifteen years, which is where the word indiction comes from. The Edict on Maximum Prices of 301 attempted to control inflation by fixing prices for some 1,400 goods and services with death as the penalty, and failed completely. The Great Persecution of Christians from 303 was the most systematic the empire attempted and also failed. He abdicated in 305, the first Roman emperor to do so voluntarily, retired to a palace at Split, and grew cabbages. The tetrarchy failed as a succession mechanism the moment he stopped supervising it. Civil war broke out within eighteen months of his abdication and ran for another eighteen years until Constantine won, and no later emperor tried to make the throne non-hereditary again.
- Year: 284 CE
- Category: Political
