The Roman Republic collapsed at the apogee of Roman military power. The legions has swept over Europe and the Middle East, from England to Egypt. The Republic ended at its wealthiest point, with trade circling from Spain to modern-day Turkey. It had conquered every rival, and faced no serious existential threat. Internally, it never knew peace.
On paper, the Republic fell because of a fatal flaw in its military — the armies were loyal to men, not the people. A republican government can only survive so long as the military is subordinate to the population at large. Generals could simply march on Rome to extract concessions. But the loyalty of the troops to one general over the people of Rome was not a founding principle of the nation. The early armies of Rome were compulsory forces gathered from the farmers who could supply their own weapons. Had these farmer armies been less effective, perhaps Rome would have remained a Republic for centuries longer — had it not been conquered by someone else. But instead, those armies were successful to an unprecedented degree. They swept over Italy and then the Mediterranean, absorbing their rivals. The wealth generated from these conquests enriched the oligarchs in the Senate and in the patrician families. The length of the wars impoverished the soldiers, whose farms at home withered while their owners fought overseas. To add insult to injury, those that failed were bought up at cheap prices by those same oligarchs. Rome’s success exposes fatal fissures in its society, polarizing the people (populares) from the oligarchs (optimates).
When, in 113 B.C., hundreds of thousands of Proto-Germanic tribes poured into Roman territory, Rome had to confront its systemic societal problems in a conclusive way. The overstretched legions has been pushed to the brink by wars of conquest. Now, in wars of survival, they were breaking like waves against a rocky beach. The Cimbrii and Teutones were second only to Hannibal when it came to killing hundreds of thousands of Romans. But unlike the Second Punic War, there was no tactical genius steering armies against Rome. Instead, it was the collective migration of hitherto unknown peoples. The armies that had proven themselves against organized states were collapsing before migrating populations.
The solution to this problem was to forego the earlier farmer armies and rely on a professional force. This policy solved two problems at once — it grew Rome’s armies and tackled long-term problems with the distribution of wealth from Roman conquests. Senators reluctant to pay for a standing army were amenable to letting the politicians proposing the measure to take financial responsibility for it. This shift expanded the population of Romans able to fight for their country, but while the decision to make the commanding general responsible for those provisions was politically expedient in the short term, it was fatally catastrophic in the long term. The originators of this policy would live long enough to be pursued by the armies of their political opponents. It was arguable whether the Republic could have survived the invasion of the Cimbrii and Teutones; history is conclusive that the Republic could not survive its generals.
When we tell this history while sidestepping the names of Marius, Sulla, and Caesar, the picture clears. The consensus of history regarding the fall of the Roman Republic — that armies loyal to powerful men were ultimately fatal to elective government — is correct. But it is all to often missed that this fateful step to Empire was undertaken as a short-term measure to battle a migrating people. The nature of the migration of the Cimbrii and Teutones isn’t just a side story to the consequences of Roman military policies. Rather, it highlights how unexpected events can resolve decades of policy stalemate in consequential ways. When we consider the migration of the Cimbrii and Teutones in a climactic context, we get a different overall picture of the Roman Republic. We see a system of government that was unable to solve its problems and incapable of adapting to its broader environment. To put it in (probably overly) biologically simplistic terms: the Roman Republic was a failed adaptation in a new environment.
Sedentary vs Mobile Strategies
Societies tend to be formed of people with a shared narrative following a similar adaptation to their environment. Sometimes that adaptation is hunting and gathering; sometimes it is sedentary farming. In their case, the societies survival depends on making more copies of itself through traditions passed down from generation to generation. That involves both people and ideas. History is replete with examples of how societies can structure themselves in different ways. The Romans and protocol-Germanic tribes represented two extremes of these adaptations to their environment. Romans settled in cities and maximized the agricultural potential and population of their territories through infrastructure. Proto-Germanic populations, by contrast, invested less their areas, and simply moved when conditions changed. One society planted a flag, another carried theirs.
This difference in how land was treated is reflected in historical accounts for why Romans waged war on another migratory people: the Gauls. Julius Caesar, in his “Gallic Wars”, states this plainly:
“After his death, the Helvetii nevertheless attempt to do that which they had resolved on, namely, to go forth from their territories. When they thought that they were at length prepared for this undertaking, they set fire to all their towns, in number about twelve — to their villages about four hundred — and to the private dwellings that remained; they burn up all the corn, except what they intend to carry with them; that after destroying the hope of a return home, they might be the more ready for undergoing all dangers. They order every one to carry forth from home for himself provisions for three months, ready ground. They persuade the Rauraci, and the Tulingi, and the Latobrigi, their neighbours, to adopt the same plan, and after burning down their towns and villages, to set out with them: and they admit to their party and unite to themselves as confederates the Boii, who had dwelt on the other side of the Rhine, and had crossed over into the Norican territory, and assaulted Noreia.” — Julius Caesar, De Bello Gallico, Book I: 5
While interpreted by Romans as acts of wars, these behaviors don’t suggest an invading army. Burning homes and villages suggests strongly that women and children weren’t staying home for whatever violence was to come. These are hallmarks of population movements. While it is still conceivable to interpret this as war, we can look to societies in present-day South America to see the same behaviors.
During the year-long El Niño episode in 1972; [the Yanomami] gardens ceased to produce and fires set in newly cleared fields spread to adjacent forests. Streams dried up, killing fish. Wild plants failed to flower or fruit, causing the deaths of animals dependent on them. The people survived by abandoning their villages and reverting to hunting and gathering until normal conditions returned. — Betty Jane Meggers, Prehistoric America: An Ethnological perspective: xiii
Archaeological evidence suggests that buts were burned prior to their abandonment as well (Randall in Sassaman and Holly: 135). In the US Southwest, the Ancestral Puebloan peoples (commonly refers to by the name Anasazi) had a similar ritual for abandonment:
Purposeful destruction of places with ritual significance has been recorded in multiple places in the Ancestral Pueblo Southwest (Van Keurens and Roos 2013; Walker 1998; Walker et al. 2000). Kivas, in particular, often show “closure” or “decommissioning,” often involving burning as part of the closing process. This can be interpreted in different ways. One likely explanation is that those most intimately involved with use of the facility expected to leave the settlement for an extended amount of time, perhaps for perpetuity. Facility destruction through burning would have ensured that others, including those with bad intentions, would not have access to this powerful place, a location where occupants of the facility come into contact with physical forces ancestors, and other aspects of the group’s belief system. Closure would ensure no future use of, or access to, this important portal in and out of the spirit world (Wilshusen 1986). — Barbara Mills and Severin Fowles 2017
Having worked extensively at Chaco Canyon, the earliest and largest large-scale Ancestral Pueblo cultural center, I can recall seeing the pink fire-cracked rocked lining the otherwise sandstone-brown on the inside of millennia-old kivas. An additional parallel is this: burning ceremonial centers and homes is consistent with the Ancestral Puebloan pattern of cremating the dead. There is no reason to think that Caesar was inaccurate when he said that the Helvetii burned down their villages, but there is every reason to think that he may be misinterpreting their intent in doing so. This does not mean that the Helvetii did not prepare for violence, migration can lead violence when entering someone else’s lands. But migration itself is not necessarily a violent act. Nor was it rare; it has been the norm in adapting to changing conditions for millions of years. The unnatural (and surprisingly recent) state of human affairs is living within defined borders. The migration of the Cimbrii and Teutones represents what happened when a traditional lifeway of migration met a more rigid system of militarized borders. When we look back on history, we interpret it through its outcomes. We lose the perspective of the people who lived through these events by knowing what would come to pass. In our time, almost every instance of a nation state encountering a migratory people, it is the migratory people who lost. But that is not the historical norm. For most of the Cimbrii-Roman interactions, it looked like the traditional migrations would overcome new borders. The Roman’s ability to withstand the migration represented a crucial turning point for history in Europe — it was states with borders that were the dominating political entity, rather than the largest tribal confederation.
Marian Reforms
It is hard to overstate how crucial the military reforms of Marius were to turning Rome’s fortunes during the Cimbrii migrations. The Roman army that was defeated by the Cimbrii was over-stretched and poorly compensated. They had been used as tools of conquest, and had sacrificed their lands to be of service to oligarchs. They were poor and demoralized, though still driven by duty to meet the existential threat pushing its way South. Each army had to be recruited from scratch by generals to meet the hour of need. As a result, they lacked the cohesion of an experienced fighting force, and the general lacked a intuitive understanding of how his mend would fight.
The armies of Marius were, by contrast, fresh, large, and provisioned — they did not have to be able to afford their own weapons. As volunteers, service in the military wasn’t just about duty, but also about advancement. They were also expensive. While the state would provision the armies, ultimate reward for service would be in the form of land-grants negotiate (or seized) by the general. This was the necessary compromise needed to get approval from the Senate of Rome, who were reluctant to relinquish their personal fortunes to finance the army.
Perhaps the largest change resulting from Marius’s reforms had less to do with military strategy and more to do with the idea of what a nation-state meant. Marius unilaterally declared all his men citizens of Rome following the conclusive battle against the Cimbrii and Teutones at Vercellae in 105 B.C. Marius justified this by claiming in the heat of battle against the enemy, he could not tell the Romans from their Italian allies. Senators in Rome were shocked and appalled by this, because in their world you were either born in Rome or you weren’t. To Marius, Roman citizenship could be achieved. This division between ascribed status — in which you were born to wealth and influence (Donald Trump) and achieved status — in which you work hard to attain wealth and influence (Barrack Obama) has played out in history over and over again. But for Rome, it’s history was as a city state, not an expansive Empire. As such, it’s governing regime was based on the needs of a single city. As Rome expanded across Italy, it hadn’t assimilated its neighbors, it had subjugated them. But Rome could not defend itself against the Cimbrii and Teutones without them. Marius understood this, and went from point A to point Z immediately — in order for Rome to face down the threat, it had to act as a cohesive Empire, at least as far as the military was concerned. This was a much harder bridge for the elites of Rome to cross — the could maybe get to point C. But to them, the city of Rome would always take precedence over the Empire of Rome. Of course, as leaders of the central city, they could claim the majority of the spoils of conquest under this structure, which strongly incentivized them to continue the governing system they inherited from their fathers.
It is here that we must zoom out and take stock at how the European and Middle Eastern world was governed at the time. We can identify 4 main types of government:
Tribal organization: this was common throughout the majority of what we today call Europe. Local strongmen controlled a manageable, migratory group of people united by language and culture. These sometimes merged to form large confederations, but the immediate tribal affinity was always the strongest loyalty. These tribes would farm plots for a year or two and then move on to richer pastures. They frequently incurred on the land of others, and disputes were resolved by the strongest fighting force.
City-States: Emerging from the Bronze Age Collapse, the most common form of government in the Mediterranean Region was the what the Greeks called the polis — a city and its immediate agricultural surroundings. Athens, Sparta, Thebes, Carthage, and Rome were all examples of these stand-alone city governments.
Ethnic Kingdoms: These were areas of a few cities and mostly agrarian land united by culture (Armenia) or religion (Judah). These were less common, but nonetheless were present.
Empires: The only Empires left standing at the time of Rome’s rise were the Hellenistic kingdoms of the generals of Alexander the Great. These included principle the Seleucid Empire of the Middle East and Ptolemaic Egypt. But the Greeks in charge of them largely left the governing structures of the earlier Persian and Egyptian dynasties intact.
Of these governing structures, there were three modes of leadership. Both City-States and Empires had a central authority figure in the King/Emperor, who then had clear underlings. Power was typically inherited, so advancement for individuals was explicitly through existing power structure. Tribal groups could have a king-like figure, but the better term would be a strongman who still had to win influence and who could be toppled by rivals. City-States tended to have more representative governments — Athens had a pure Democracy while Rome had a Republic. In a few instances, namely Sparta, there were still kings who inherited power, but their powers were subject to review and consent from other institutions in the city. The City-States had these more representative forms of government because they were A) smaller and B) defense required volunteer military service. While the Persian Emperor could command an army by raw power, the city had to ask citizens for help because it was a much smaller entity. As such, the citizens of an Athens or Rome had much more power over their government than the citizens of Susa or Parsagarda had over the Persian Empire. If we look at the history of Rome in particular, we see multiple examples of the citizens using their leverage over the elites to gian rights. The Office of Tribune of the Plebs in Rome, the same office both of the Gracchi brothers would use to argue for land grants for soldiers, sad itself the product of a compromise between the Senators of Rome and the citizens whose support they ultimately needed.
The problem with Rome in the time of Marius was that it had the government for a city-state in charge of the lands of an Empire. This was not the only time such a situation had happened — Carthage controlled much of Hispanic (present-day Spain) from their Capitol in North Africa (present-day Tunis) but it was the sheer scale of Rome’s territory that set it apart. By land alone, it’s only peer was the Achaemenid Persian Empire of old. Yet it stubbornly held onto the governing constitution of the city. This introduced a dangerous dynamic in the city for two reasons. The first was simple efficiency — a group of good-old boys in one city in Italy made the decisions for the economies of Spain, North Africa, and Greece. The second was wealth — in the past the Roman elite ultimately received their wealth from the farmers and miners in Rome and its neighbors. As such, they had a dependency in social stability. As Rome’s conquests grew more far flung, their wealth increasingly came from abroad. This lessened the dependency of the elites on their city. The volunteer armies of Rome who had fought in those wars had increasingly grown deeply angry at the wealth of those elites from the same wars. And to rub valuable salt into the wound, they could come home after years of conquest to a collapsing farm drowning in debt that would then be taken by those same elites. But the farm that the elites took paled in value to the booty overseas. It wasn’t just gold that came from conquered neighbors, but slaves as well. Dispossessed former farm workers found their jobs replaced by hundreds of thousands of slaves pouring into the Italian countryside. As the overal wealth of Rome grew, the deeper into poverty the average Roman sank. The Gracchi brothers recognized the fault line emerging. Both would die violently by elites who felt emboldened by their increasingly international revenue to ride roughshod over local affairs. The Roman Republic had a city’s solutions to international problems.
The immediate consequence of the Marian Reforms was a victory over the Cimbrii and Teutones that established the cohesiveness of Rome’s military dominance over Europe. But its ultimate meeting was while the military was organized to serve an Empire, the administration of Rome would continue to serve a city. The lands that Rome now held power over included Italy, Greece, Spain, and portions of North Africa. The vision of the Senators of Rome was unsustainable and divorced form the reality of the vast lands and peoples under its control. For Rome and it’s allies, the most obvious path to personal advancement was in the military. It was for the vast majority of Roman subjects the only means of obtaining land and thus financial security. As such, their route professionally was not through the city government of Rome, but instead through the generals who were responsible for providing land grants.
Which, ironically, was the very issue the Gracchi brothers had hoped to solve a generation earlier. On the face of it, Marius’ solution was a win-win for everyone. Roman soldiers would not be impoverished by the obligation to serve in the military — the could even be enriched by it if the campaign was successful. The Senators of Rome did not have to sacrifice their personal wealth to make this happen — they only needed to provide arms and equipment to support recruits who did not own land. And Rome’s military effectiveness was greatly increased — they had dominated Greece and Carthage with their volunteer forces, what could they now accomplish with a professional standing army? Marius would have done well to congratulate himself on solving so many seemingly intractable issues — ranting from generational wealth inequality to immediate risk of the Cimbrii-Teutones invasion. His leadership was indeed brilliant on both fronts. But it would not take long at all for the flaws in his system to emerge, and envelop both Rome and himself. And the source of the demise of the Roman Republic would come from his greatest source of pride — his camaraderie with his fellow soldiers.
The increased power of Roman generals was realized by Marius’s rival Sulla, who would turn his armies on the citizens of Rome itself. While Sulla would stop short of ending the Republic, a younger generation that included Julius Caesar and Pompey would see the inevitable consequences of a city government ruling an Empire. The transition to an Empire solves these problems in a fell swoop — the militaries were now loyal to the Emperor, all provinces were now governed as equal(ish) partners, and the political rivalries in Rome were more or less settled. This is perhaps the inevitable endpoint of the Republic.
Breaking the Climate-Migration Link
If we zoom out — wayyyyyy out — and look at the Cimbrii/Teutones migrations, it forms a familiar pattern. Populations grow during times of plenty, and migrate to greener pastures in times of scarcity. This has been the behavior of humans since long before we began to walk. The Cimbri and Teutones did what all humans for all of our prehistory have always done.
The Romans, by contrast, had a radically different strategy. Not only did they stay put despite adversity, they incorporated multiple environments into their Empire. The Nile fed agriculture in a desert independent of rain, so when drought struck Italy, bread came from the South. If Gaul had a bumper year of crops, it could help shortfalls in the Middle East. This was by no means a perfect system, as transportation of goods before combustion engines and refrigeration was neither easy nor cheap. But it meant that as a political unit, environmental diversity within borders made it impossible for a climatic downturn to sink all ships. This made Rome not only radically different than our traditional history as migratory hunters and gatherers, but radically different from other sedentary societies. And by marshaling all these resources under one banner, the Romans could stop prehistory. When I taught world archaeology classes, it was natural to stop at the agglomeration of societies into the empires of Rome and Han Dynasty China. They represented a pivot from a world of isolated cultures making first contact to one of federalized empires and currency.
The wave of migratory Teutones and Cimbri, itself a pattern of tribal existance in Europe as long as people have occupied the subcontinent, broke against Rome — but only just. A few surprises on the battlefield — weather, a smart (or decidedly not smart) maneuvere, and history would have washed away by prehistory. The Romans could have lost the last battle, and the Cimbri and Teutones would have marched to the riches in the South. One can imagine the Roman Empire being a mere blip in history, and Germanic languages being spoken in Italy while Celtic languages persisted in Spain and France.
The Cimbri and Teutones were pushed back, but at tremendous social cost. The Roman form of government was not up to the task, and its military changed much faster than its government. This led to revolution, and Empire. The Rome that followed Augustus was better organized that the Republic that couldn’t stay out of war with itself. It could lean on its wealth and ecological diversity to ride out the kinds of storms that would break smaller nations. But surprisingly, those storms never came. The next two hundred years of Roman history are collectively called the “Pax Romana” — a long period of economic growth with only minor conflicts at Rome’s borders. This long summer was not only a political or economic event. Climatic indicators, whether global records stored in ice caps or tree rings subsumed by oxygen poor bogs all tell the same story — a 200 year period of remarkable stability.
