Crisis of the Third Century

From the beginning of the Principate there were no clear rules for the imperial succession, largely because the empire maintained the facade of a republic.[22]

During the early Principate, the process for becoming an emperor relied on a combination of proclamation by the Senate, popular approval, and acceptance by the army, in particular the Praetorian Guard. A family connection to a previous emperor was beneficial, but it did not determine the issue in the way a formal system of hereditary succession would. From the Julio-Claudian dynasty onwards was sometimes tension between the Senate's preferred choice and the army. As the Senatorial class declined in political influence and more generals were recruited from the provinces this tension increased.

Whenever the succession appeared uncertain, there was an incentive for any general with support of a sizable army to attempt to seize power, sparking civil war. The most recent example of this prior to the Crisis was the Year of the Five Emperors which resulted in the victory of Septimius Severus. After the overthrow of the Severan dynasty, for the rest of the 3rd Century, Rome was ruled by a series of generals, coming into power through frequent civil wars which devastated the empire.[23]

The first and most immediately disastrous of the natural disasters that the Roman Empire faced during the Third Century was the plague. The Antonine Plague that preceded the Crisis of the Third Century sapped manpower from Roman armies and proved disastrous for the Roman economy.[24] From 249 AD to 262 AD, the Plague of Cyprian devastated the Roman Empire so much so that some cities, such as the city of Alexandria, experienced a 62% decline in population. These plagues greatly hindered the Roman Empire's ability to ward off barbarian invasions but also factored into problems such as famine, with many farms becoming abandoned and unproductive.[25]

A second and longer-term natural disaster that took place during the Third Century was the increased variability of weather. Drier summers meant less agricultural productivity and more extreme weather events led to agricultural instability. This could also have contributed to the increased barbarian pressure on Roman borders, as they too would have experienced the detrimental effects of climate change and sought to push inward to more productive regions of the Mediterranean.[26]

Barbarian invasions against the Roman Empire in the 3rd century

Barbarian invasions came in the wake of civil war, plague, and famine. Distress caused in part by the changing climate led various barbarian tribes to push into Roman territory. Other tribes coalesced into more formidable entities (notably the Alamanni and Franks), or were pushed out of their former territories by more dangerous peoples such as the Sarmatians (the Huns did not appear west of the Volga for another century). Eventually, the frontiers were stabilized by the Illyrian Emperors. However, barbarian migrations into the empire continued in greater and greater numbers. Though these migrants were initially closely monitored and assimilated, later tribes eventually entered the Roman Empire en masse with their weapons, giving only token recognition of Roman authority.[27]

The defensive battles that Rome had to endure on the Danube since the 230s, however, paled in comparison to the threat the empire faced in the East. There, Sassanid Persia represented a far greater danger to Rome than the isolated attacks of Germanic tribes.[28] The Sassanids had in 224 and 226 overthrown the Parthian Arsacids, and the Persian King Ardashir I, who also wanted to prove his legitimacy through military successes, had already penetrated into Roman territory at the time of Severus Alexander, probably taking the strategically important cities of Nisibis and Carrhae.[29]

One of the most profound and lasting effects of the Crisis of the Third Century was the disruption of Rome's extensive internal trade network. Ever since the Pax Romana, starting with Augustus, the empire's economy had depended in large part on trade between Mediterranean ports and across the extensive road systems to the Empire's interior. Merchants could travel from one end of the empire to the other in relative safety within a few weeks, moving agricultural goods produced in the provinces to the cities, and manufactured goods produced by the great cities of the East to the more rural provinces.

Large estates produced cash crops for export and used the resulting revenues to import food and urban manufactured goods. This resulted in a great deal of economic interdependence among the empire's inhabitants. The historian Henry St. Lawrence Beaufort Moss describes the situation as it stood before the crisis:

Along these roads passed an ever-increasing traffic, not only of troops and officials but of traders, merchandise and even tourists. An interchange of goods between the various provinces rapidly developed, which soon reached a scale unprecedented in the previous history and not repeated until a few centuries ago. Metals mined in the uplands of Western Europe, hides, fleeces, and livestock from the pastoral districts of Britain, Spain, and the shores of the Black Sea, wine and oil from Provence and Aquitaine, timber, pitch and wax from South Russia and northern Anatolia, dried fruits from Syria, marble from the Aegean coasts, and – most important of all – grain from the wheat-growing districts of North Africa, Egypt, and the Danube Valley for the needs of the great cities; all these commodities, under the influence of a highly organized system of transport and marketing, moved freely from one corner of the Empire to the other.[32]

With the onset of the Crisis of the Third Century, however, this vast internal trade network broke down. The widespread civil unrest made it no longer safe for merchants to travel as they once had, and the financial crisis that struck made exchange very difficult with the debased currency. This produced profound changes that, in many ways, foreshadowed the very decentralized economic character of the coming Middle Ages.[33]

Large landowners, no longer able to successfully export their crops over long distances, began producing food for subsistence and local barter. Rather than import manufactured goods from the empire's great urban areas, they began to manufacture many goods locally, often on their own estates, thus beginning the self-sufficient "house economy" that would become commonplace in later centuries, reaching its final form in the manorialism of the Middle Ages. The common, free people of the Roman cities, meanwhile, began to move out into the countryside in search of food and better protection.[34]

Made desperate by economic necessity, many of these former city dwellers, as well as many small farmers, were forced to give up hard-earned basic civil rights in order to receive protection from large land-holders. In doing so, they became a half-free class of Roman citizen known as coloni. They were tied to the land, and in later Imperial law, their status was made hereditary. This provided an early model for serfdom, the origins of medieval feudal society and of the medieval peasantry. The decline in commerce between the imperial provinces put them on a path toward increased self-sufficiency. Large landowners, who had become more self-sufficient, became less mindful of Rome's central authority, particularly in the Western Empire, and were downright hostile toward its tax collectors. The measure of wealth at this time began to have less to do with wielding urban civil authority and more to do with controlling large agricultural estates in rural regions since this guaranteed access to the only economic resource of real value — agricultural land and the crops it produced. The common people of the empire lost economic and political status to the land-holding nobility, and the commercial middle classes waned along with their trade-derived livelihoods. The Crisis of the Third Century thus marked the beginning of a long gradual process that would transform the ancient world of Classical antiquity into the medieval one of the Early Middle Ages.[35]

However, although the burdens on the population increased, especially the lower strata of the population, this can not be generalized to the whole empire, especially since the living conditions were not uniform. Although the structural integrity of the economy suffered from the military conflicts of that time and the inflationary episode of the 270s, it did not collapse, especially because of the complex regional differences. Recent research has shown that there were regions that prospered even further, such as Egypt, Africa and Hispania. But even for Asia Minor, which was directly affected by attacks, no general decline can be observed.[36] While commerce and the economy flourished in several regions, with several provinces not affected by hostilities, other provinces experienced some serious problems, as evidenced by personal hoards in the northwestern provinces of the empire. However, there can be no talk of a general economic crisis throughout the whole of Empire.[37]

Even the Roman cities began to change in character. The large cities of classical antiquity slowly gave way to the smaller, walled cities that became common in the Middle Ages. These changes were not restricted to the third century, but took place slowly over a long period, and were punctuated with many temporary reversals. In spite of extensive reforms by later emperors, however, the Roman trade network was never able to fully recover to what it had been during the Pax Romana (27 BC-AD 180). This economic decline was far more noticeable and important in the western part of the empire, which was also invaded by barbarian tribes several times during the century. Hence, the balance of power clearly shifted eastward during this period, as evidenced by the choice of Diocletian to rule from Nicomedia in Asia Minor, putting his second in command, Maximian, in Milan. This would have a considerable impact on the later development of the empire with a richer, more stable eastern empire surviving the end of Roman rule in the west.[38]

While imperial revenues fell, imperial expenses rose sharply. More soldiers, greater proportions of cavalry, and the ruinous expense of walling in cities all added to the toll. Goods and services previously paid for by the government were now demanded in addition to monetary taxes. The empire suffered from a crippling labour shortage. The steady exodus of both rich and poor from the cities and now-unprofitable professions forced Diocletian to use compulsion; conscription was made universal, most trades were made hereditary, and workers could not legally leave their jobs or travel elsewhere to seek better-paying ones. This included the unwanted middle-class civil service positions and under Constantine, the military. Constantine also tried to provide social programs for the poor to reduce the labour shortage.[39]

All the Barracks Emperors based their power on the military and on the soldiers of the field armies, not on the Praetorians in Rome. Thus, Rome lost its role as the political center of the empire during the third century, although it remained ideologically important. In order to legitimize and secure their rule, the emperors of the third century needed above all military successes.[40]

The centre of decision-making shifted away from Rome and to wherever the emperor was with his armies, typically, in the east. This led to the transfer of the capital to the four cities Milan, Trier, Nicomedia, and Sirmium, and then to Constantinople. The Senate ceased to be the main governing organ and instead members of the equestrian class who filled the military officer corps became increasingly prominent.[41]