page_title: Tetrarchy
section_title: Demise
hierarchical_section_title: Tetrarchy / Demise
context_page_description: The Tetrarchy is the term adopted to describe the system of government of the ancient Roman Empire instituted by Roman Emperor Diocletian in 293, marking the end of the Crisis of the Third Century and the recovery of the Roman Empire. The government of the empire was divided between the two senior emperors, the augusti, and their juniors and designated successors, the caesares.
  Initially Diocletian chose Maximian as his caesar in 285, raising him to co-augustus the following year; Maximian was to govern the western provinces and Diocletian would administer the eastern ones. The role of the augustus was likened to Jupiter, while his caesar was akin to Jupiter's son Hercules. Galerius and Constantius were appointed caesares in March 293. Diocletian and Maximian retired on 1 May 305, raising Galerius and Constantius to the rank of augustus. Their places as caesares were in turn taken by Valerius Severus and Maximinus Daia.
  The orderly system of two senior and two junior emperors endured until Constantius died in July 306, and his son Constantine was unilaterally acclaimed augustus and caesar by his father's army.
context_section_description: 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 new Caesares were appointed: Maximinus (Caesar to Galerius) and Flavius Valerius Severus (Caesar to Constantius). These four formed the second tetrarchy.
  However, the system broke down very quickly thereafter. When Constantius died in 306, Galerius promoted Severus to Augustus while Constantine, Constantius' son, was proclaimed Augustus by his father's troops. At the same time, Maxentius, the son of Maximian, who also resented being left out of the new arrangements, defeated Severus before forcing him to abdicate and then arranging his murder in 307. Maxentius and Maximian both then declared themselves Augusti. By 308 there were therefore no fewer than four claimants to the rank of Augustus (Galerius, Constantine, Maximian and Maxentius), and only one to that of Caesar (Maximinus).
  In 308 Galerius, together with the retired emperor Diocletian and the supposedly retired Maximian, called an imperial "conference" at Carnuntum on the River Danube. The council agreed that Licinius would become Augustus in the West, with Constantine as his Caesar. In the East, Galerius remained Augustus and Maximinus remained his Caesar. Maximian was to retire, and Maxentius was declared a usurper. This agreement proved disastrous: by 308 Maxentius had become de facto ruler of Italy and Africa even without any imperial rank, and neither Constantine nor Maximinus—who had both been Caesares since 306 and 305 respectively—were prepared to tolerate the promotion of the Augustus Licinius as their superior.
  After an abortive attempt to placate both Constantine and Maximinus with the meaningless title filius Augusti ("son of the Augustus"), essentially an alternative title for Caesar), they both had to be recognised as Augusti in 309. However, four full Augusti all at odds with each other did not bode well for the tetrarchic system.
  Between 309 and 313 most of the claimants to the imperial office died or were killed in various civil wars. Constantine forced Maximian's suicide in 310. Galerius died naturally in 311. Maxentius was defeated by Constantine at the Battle of the Milvian Bridge in 312 and subsequently killed. Maximinus committed suicide at Tarsus in 313 after being defeated in battle by Licinius.
  By 313, therefore, there remained only two emperors: Constantine in the West and Licinius in the East. The tetrarchic system was at an end, although it took until 324 for Constantine to finally defeat Licinius, reunite the two halves of the Roman Empire and declare himself sole Augustus.
caption: Constantine at the battle of the Milvian Bridge, fresco by Raphael, Vatican Rooms.
exif: {}