The "Crisis of the Third Century" (also known as the "Military Anarchy" or the "Imperial Crisis" ) is a commonly applied name for the crumbling and near collapse of the Roman Empire between 235 and 284 caused by the three simultaneous crises of external invasion, internal civil war and economic collapse. The changes in the institutions, society, economic life and eventually religion were so profound and fundamental, the "Crisis of the Third Century" is increasingly seen as the watershed marking the difference between the classical world and the early mediaeval world, or world of late antiquity.

During this roughly half-century period, three crises, any one of which were a singular threat to the Empire, came together in a perfect storm: external invasions, internal civil wars and a runaway hyperinflation economy. The future viability of the Empire, by all reasonable standards, should have come to an end; only through a series of tough soldier emperors and the measures of Diocletian in 284 to split the empire in half and other reforms allowed it to continue, eventually entering a new phase known as the "Dominate," the "Tetrarchy," and the "Later Roman Empire".

During this period, Rome was ruled by roughly 20 to 25 individuals, the exact number a matter of debate since so many claimed the title at the same time. Most of them were prominent generals who assumed Imperial power over all or part of the empire, only to lose it by defeat in battle, murder, or death, ruling on average only 2 to 3 years.

The troubles began in 235, when the emperor Alexander Severus was murdered by soldiers at the age of 27 after Roman legions were defeated in a campaign against Persia. As general after general squabbled over control of the empire, the frontiers were neglected and subjected to frequent raids by Carpians, Goths, Vandals and Alamanni, and outright attacks from Sassanids in the east.

Finally, by 258, the attacks were coming from within, when the Empire broke up in to three seperate competing states. The Roman provinces of Gaul, Britain and Hispania broke off to form the Gallic Empire, and two years later in 260, the eastern provinces of Syria, Palestine and Egypt became independent as the Palmyrene Empire (with Persian backing), leaving the remaining Italian centered Roman empire proper in the middle.

An invasion by a vast host of Goths was beaten back at the Battle of Naissus in 268. This victory was significant as the turning point of the crisis, when a series of tough energetic soldier emperors took power. Victories by the emperor Claudius II Gothicus over the next two years drove back the Alamanni and recovered Hispania from the Gallic Empire. When Claudius died in 270 of the plague, Aurelian, who had commanded the cavalry at Naissus, succeeded him as emperor and continued the restoration of the empire.

Aurelian brought the empire through the worst of the crisis during his reign (270-275) by hammering, in succession, the Vandals, Visigoths, Palmyrenes (see Queen Zenobia), Persians, and then the remainder of the Gallic Empire. By late 274, the Roman Empire was reunited, and the frontier troops back in place. More than a century would pass before Rome again lost the upper hand on its external enemies.

Internally the empire faced runaway hyperinflation caused by years of coinage dilution. As each of the short-lived emperors took power they needed ways to raise money quickly to pay the military and the easiest way to do so was by simply cutting how much silver was in coins with less valuable metals. This had the predictable effect of causing runaway inflation and by the time Diocletian came to power the economy of the Roman Empire was nearly collapsed; the currency had almost no valuation and trade was by barter. Every aspect of the Roman way of life was affected.

Finally, although Aurelian had played a significant role in restoring the Empire's borders for the moment from external threat, more fundamental problems remained that had caused the crisis to begin with. In particular the right of succession had never been clearly defined in the Roman Empire leading to continuous civil wars as competing factions in the military, senate and other parties put forward their favoured candidate for Emperor. Another problem was the sheer size of the Empire making it difficult for a single autocratic ruler to effectively manage multiple threats at the same time. All of these continuing problems would be radically addressed by Diocletian allowing the Empire to continue for at least another 100 years, and in the east, for another thousand years.

See these articles for more information on the leading figures or events of this time period:

• Aurelian
• Claudius II
• Diocletian
• Gallienus
• Postumus
• Roman Emperor (Crisis of the Third Century)
• Battle of Naissus
• Battle of Lake Benacus
• Zenobia

References

• Alaric Watson, Aurelian and the Third Century (Taylor & Francis, 2004) ISBN 0415301874
• John F. White, Restorer of the World: The Roman Emperor Aurelian (Spellmount, 2004) ISBN 1862272506