Imperium: How Rome became an Empire
The word Empire has two meanings. One is that of state ruling over great swathes of territory with a wide variety of peoples. Using that terminology, the late Roman Republic was an Empire as it ruled much of Mediterranean. The other is the form of government with an Emperor as absolute ruler; Rome became an ‘Empire’ in 27 BC with Augustus becoming Princeps (though officially Rome was still a Republic).
This post aims to give a rather short explanation of how Rome became an empire in both senses of the word: that is how a small city-state in the Tiber River managed to create a Mediterranean-wide empire and how the Res Publica transformed into the monarchical entity known as the Principate.
Factors of Imperial Expansion
Rome expanded rapidly. In 400 BC it was still a rather minor power that did not even fully controlled the River Tiber. Four hundred years later it had conquered everything from the English Channel to the Euphrates and southern Egypt. Here I shall focus more on the factors that allowed this rapid expansion instead of giving a strictly chronological account.
The Republican System
The Roman Republic synthesized elements of aristocracy, democracy and monarchy. It fostered a consensus between the elites regarding the rotation of leading families in power, which prevented civil wars and tyrannies for a long time, until the final century of the Republic to be more precise, by which time the Roman state had already subjugated a large number of territories. This extraordinary stability allowed the Romans to focus their energies on warring against their external enemies.
The Roman political system also fostered competition between the aristocrats. The Roman aristocrats needed Auctoritas, prestige which gave them (political) authority. This was especially true for Consuls who had only a year to do something great. Victorious generals would be granted a triumph and be treated as if they were a God that day. This struggle for glory (certamen gloriae) made for a very warlike aristocratic class.
The ordinary citizens too could be expected to benefit from such campaigns and as such they wholeheartedly supported Rome’s militarism. In an economy based primarily on farming and warfare, Rome’s ability to seize land from its enemies very visibly improved the life of ordinary citizens.
As such, the Roman state was extremely warlike even by ancient standards. It went to war almost every years since the 350s. While Hannibal was still ravaging Italy, the Romans were willing to send armed forces to campaign against the Macedonians (First Macedonian War — 214–205 BC). The Roman willingness to go to war gave them an edge over their opponents.
Roman attitudes to non-Romans and Italian elites
Manpower is of vital importance for any state to expand. The Romans were able to garner more manpower than any other ancient Mediterranean state. When Hannibal invaded Italy during the Second Punic War, in only 20 months Rome had lost 150,00 men, one fifth of the entire population of male citizens over 17. Overall, Rome may have suffered 300,000 casualties. Yet it was still able to field large armies and fight on. In 225, Rome and Campania alone could provide 250,000 infantry and 23,000 cavalry.
The Romans, in their conquests, enslaved many peoples and used them for manual labor, thus freeing up Roman farmers for military service who would otherwise be laboring. More than a few those slaves were eventually freed and were granted some political rights (freedmen). The Romans allowed conquered peoples to serve in the Roman army in exchange for giving them Roman citizenship once their service (after 20 -25 years) ended. Unlike Greeks (such as the Athenian and Spartans) who gave citizenship only to natives (and refused to integrate into their citizen body their fellow Greeks from other cities), the Romans gave citizenship (either Roman or Latin) to many Italian allied communities. This granted them not only privileges but also duties towards the Roman state and ensured both their loyalty and their service in the Roman army.
Rome used bilateral treaties in perpetuity to deal with the Italian communities. Those treaties turned part of their lands into Roman ‘public’ land and enforced a system of conscription. The Italian allies were a large component of the Roman military machine. The system worked because local Italian elites were accommodated. Each community had a patron in the Senate who ensured that their interests could be taken care of. The Romans also did not interfere much with local administration, thus allowing the elites to have much autonomy.
The Romans also established colonies (which they kept under tight control) in strategic locations in Italy which allowed them to control the peninsula and keep the Italian allies under control. Those colonies (whose population gradually increased) had the added advantage of increasing Rome’s military manpower.
The Roman Army
The Roman military machine was one of the major reasons for the Roman expansion. As stated above, the Romans were never short on manpower due to the fact that they incorporated large number of non-Romans into their military body and were able to muster a large number of allied soldiers.
The core of the Roman military was the legion, heavy infantry that during the early and mid Republic was raised from among the property owning citizens of the state. After Gaius Marius’ reforms, the Roman military was professionalized and its quality this increased even further. The standard sword of all legionaries was the gladius, a Spanish cut and thrust sword. It was among the most deadly weapons of antiquity. They also carried the scutum, an oval shield.
The legions were far more flexible as a military unit than the phalanx the Greeks used. The phalanx relied a lot on cohesion and that could be disrupted in rough terrain. In the Battle of Pydna in 168 BC, the Roman legions’ flexibility was able to defeat the rigidity of the Greek phalanx.
The Romans, according to Polybius, were adaptable to change:
they swiftly imitated them [Greek arms], for the Romans are better than
anyone at changing their practices and emulating what they see to be better
(6.25.11).
The Romans also had draconian discipline, good organization and a military ethos. An example of this was the practice of ‘decimation’, punishment that stated that a unit that abandoned a position in the face of the enemy would have a tenth of its members, selected by lot, put to death. Such measures ensured that the Romans tended to be well-trained and very disciplined. Most Roman military units had also seen more than their fair share of fighting as Rome was very warlike. As such, Roman soldiers were in a lot of cases battle-hardened veterans with much military experience. The Italian allies were of similar quality, considering the trust Roman commanders showed to them.
Logistics and communications were also of vital importance and the Romans were pretty good at them, which gave them an edge. This organization advantage allowed the Romans to fight long wars in foreign territory.
Rome Dominant
From 380s to 338, the Romans were able to impose their rule on the Latins to the east and south of the city. From 327 to 272, the Romans were able to dominate the Italian peninsula up to the Arno. From 264 to 241, the Romans fought the the First Carthaginian War. After a protracted struggle, they were able to defeat the Phoenician city state and take control of Sicily, Sardinia, and Corsica. Rome faced its greatest challenge in the Second Carthaginian War (218–202), as Hannibal crossed the Alps and inflicted terrible defeats on them. However the Romans prevailed and became the dominant power in the western Mediterranean. In 190, the Romans defeated the Seleucid Empire (one of Alexander’s successor states based in Syria), thus gaining naval dominance over the eastern Mediterranean. As already state above, the Roman legions crushed the Macedonian phalanx in the Battle of Pydna in 168 BC, thus establishing Roman control over the region. Meanwhile, the Romans had began expanding in northern Spain (since 179). Until then, the Romans had been a mainly Mediterranean power. It was in the 50s that Julius Caesar directed Roman expansion northwards. Caesar pushed Roman frontiers to the Rhine while his successor Augustus to the Danube.
From Res Publica to Principate
As already stated above, Rome had a republican system of governance. The system attempted (rather successfully considering how long it lasted) to prevent one person or family from monopolizing state power. It synthesized aristocracy (as noble families dominated the political scene) with democracy (with Roman citizens having clearly stated rights). Although the republican system worked well, it was eventually undermined by its very own success.
The Fall of the Republic
The constant wars overseas and the need to campaign in faraway territories (such as Asia Minor and Hispania) as the Roman Republic entered the Hellenistic Word and annexed provinces led to devastation for the farmers who constituted most of the troops: their farms were not cultivated while large landowners using slave labor got them out of business. This led to social unrest.
Tiberius Gracchus, a populist aristocrat, offered an ambitious reformist proposal of redistributing lands to the poorest citizens. His opponents, not unfairly perhaps, accused him of attempting to undermine the Res Publica and claimed that he wanted to declare himself King. He had already violated constitutional norms before (having overruled a tribunician veto). Thus he was assassinated by conservative senators. Twelve years later, the younger Gracchus was also assassinated.
Gaius Marius (157 BC — January 13, 86 BC), a Roman general, partially solved Rome’s problem with his reforms. He created a standing professional army which included landless Romans and replaced the old army that was based on property owning citizens. While this new army performed very well on the field of battle, the soldiers gave their allegiance not to the state but rather to the general who led them to victory and provided them with the spoils of war. This was natural as the soldiers bonded with their commander, who was usually risking his life alongside them, and not with the Senators back in Rome. Those reforms also failed to completely alleviate social unrest.
Some aristocrats saw in the popular discontent a chance to gain power. Those formed the Populares, the populist faction who campaigned the cause of the disaffected. Their opponents were the Optimates, the conservative faction. As Cicero, a supporter of the Optimates, stated:
There have always been two kinds of men in this community who have been active in politics and have striven for public distinction. One kind has wanted to be and to be considered popularis, the other the optimates: those who wished their deeds and words to be pleasing to the masses [multitudini] were considered populares, those on the other hand who aimed to have their policies approved by all the best people were considered optimates (On Behalf of Sestius 96)
The Populares as well as some of the Optimates saw in the new, professionalized army of Marius the means with which they could gain power since the soldiers were more loyal to their general than to the Roman state. Ambitious generals such as Sulla used the army in domestic conflicts; Sulla marched on Rome twice and became dictator thanks to the support of the soldiers. Sulla rewarded his supporters with land he appropriated in Italy from Roman citizens who were his political opponents, something that would have been impossible in earlier years.
Julius Caesar was, though, by far the most successful of the generals who used the army to gain political power. After his success in Gaul (58–51 BC), his enemies tried to eliminate him and thus he moved his army against the Republic. Caesar of course, being a master in propaganda (a much needed skill for any politician), used populistic rhetoric to justify his move: he claimed that his march to Italy was ‘to reclaim liberty for himself and for the Roman people oppressed by a faction of the few’ (On the Civil War 1.22.5). Being a military genius, Caesar managed to defeat his opponents in a series of rapid campaigns. His end came when he was assassinated in 44 BC. His opponents hoped that this assassination would prevent the fall of the Republic and the emergence of one-man tyranny. But by this time, the republican system was already too dysfunctional to be saved.
Octavian Caesar Augustus — Rome’s First Emperor
The man who would put an end to the old system and become the first Emperor of Rome was Gaius Octavian, nephew of Julius Caesar. He was able to capitalize on the name of his uncle (calling himself Octavian Caesar and deifying his uncle) to gain the loyalty of Caesar’s troops. He was able to defeat his rivals and ensure his supremacy in the Roman world by 31 BC (with the victory of his forces at the naval battle of Actium).
Augustus did not present himself as the founder of an empire but rather as the restorer of the Roman Republic. He did not alter the republican institutions; assemblies continued to be held as before and Augustus even distributed bribes to make elections look authentic.
Nevertheless, he took for himself the position of princeps and was the effective ruler of Rome:
- he was granted tribunal powers (to convene the Senate and people, veto the actions of assemblies and Senate, preside over elections and speak first at meetings).
- he purged his enemies in the Senate in 29 BC.
- he ensured direct control of the provinces in which legions were stationed.
- he formed the Praetorian Guards, allowing him to gain control over Rome.
His military supremacy allowed him to be the supreme ruler of the Roman world, even if officially the state was still a republic. Thus, although in name the Res Publica still existed, Rome was now an imperial monarchy.
Augustus also reformed revenue collection, bringing large parts of Rome’s empire under consistent direct taxation instead of asking for intermittent tributes. Taxation was determined by population census and private tax farming was abolished in favor for civil service tax collectors. This made provincial administration far more tolerable, decreased corruption and oppression and increased revenues.
When he died in 14 AD, Rome had been transformed to an imperial dynastic state.
