The term tetrarchy (from the Greek: τετραρχία, tetrarchia, "leadership of four [people]") describes any form of government where power is divided among four individuals.
Although the term … See more

Although power was shared in the tetrarchic system, the public image of the four members of the imperial college was carefully managed to give the appearance of a united empire … See more

When in 305 the 20-year term of Diocletian and Maximian ended, both abdicated. Their caesares, Galerius and Constantius Chlorus, were both raised to the rank of augustus, and two … See more

The first phase, sometimes referred to as the diarchy ("rule of two"), involved the designation of the general Maximian as co-emperor—firstly as See more

The four tetrarchs based themselves not at Rome but in other cities closer to the frontiers, mainly intended as headquarters for the defence of the empire against bordering rivals … See more

One of the greatest problems facing emperors in the Third Century Crisis was that they were only ever able to personally command troops on … See more

Although the tetrarchic system as such only lasted until 313, many aspects of it survived. The fourfold regional division of the empire continued in the form of Praetorian prefectures, each of which was overseen by a praetorian prefect and subdivided into … See more