The Roman Republic: Government, Law, and the Rise of a Superpower

In 509 BCE, a generation after the last of the seven kings was driven into exile, the Romans made a decision that would shape the next four and a half centuries of their history and, through them, the political imagination of the West. They abolished the monarchy. In its place they built a state without a king, governed by annually elected magistrates, advised by a permanent council of elder statesmen, and constrained by written law. They called it the res publica — “the public thing” — and from its apparently modest beginnings on the banks of the Tiber it would, by the time of its collapse, rule the entire Mediterranean world.

The Roman Republic was not a democracy in the modern sense. It was an oligarchy that gradually, and never quite completely, opened itself to the claims of the common people. Its genius was not theoretical but practical: a constitution flexible enough to govern a city-state, then a regional power, and finally a continent-spanning empire without ever being formally rewritten. When it finally collapsed, it collapsed not from institutional weakness but from the success of its own conquests, which overwhelmed the small agrarian society for which it had been designed.

The Constitution of the Republic

The Romans themselves believed that their constitution was unique because it was a mixta res publica, a “mixed regime” that combined the three good forms of government identified by the Greek philosopher Polybius: monarchy, aristocracy, and democracy. The consuls held the imperium, the supreme executive power; the Roman Senate represented the wisdom and authority of the patrician and wealthy classes; and the popular assemblies represented the sovereign will of the Roman people.

This balance of powers was, in practice, heavily weighted toward the aristocracy. The consuls, two in number and elected annually, were the chief executives of the state. They commanded the army in the field, presided over the Senate and the assemblies, and represented Rome in foreign affairs. Below them were the praetors, who administered justice, and the censors, who maintained the rolls of citizens and supervised public morality. Aediles looked after the streets, the markets, and the public games. Quaestors managed the finances. The magistracies were arranged in a strict hierarchy known as the cursus honorum, the “course of honors,” which dictated the order in which they could be held.

All magistrates were elected, and almost all served for one-year terms. The principle of collegiality meant that each magistrate had a colleague with equal power, who could veto his decisions. The principle of annuality prevented any individual from accumulating too much personal authority. Combined, the two principles made it difficult for any Roman to behave like a king — at least in theory.

The Senate: The Real Center of Power

The Senate was not an elected body. It was composed of ex-magistrates, appointed for life by the censors from among those who had held high office. By the late Republic it numbered about 600 members, although the inner circle of former consuls — the consulares — was much smaller and far more influential. The Senate had no formal constitutional power, but its auctoritas, its moral and advisory authority, was immense. It controlled the public finances, directed foreign policy, assigned provinces to magistrates, and — most importantly — advised on strategy in time of war.

Senators were drawn from a narrow aristocratic elite. To be a senator in the late Republic, a man had to possess a property qualification of one million sesterces and to have held at least the quaestorship. The Senate met in the Curia in the Roman Forum, and its debates, though sometimes vigorous, were usually closed. Senators were not paid for their service, which effectively excluded the poor from the body.

The Senate’s power was real but unwritten. The Republic had no single constitutional document; it had a collection of laws, customs, precedents, and traditions that evolved over centuries. The Senate could not pass laws, but the popular assemblies rarely voted against its recommendations. A consul who flouted the Senate could expect to be vetoed by his colleague, attacked in the press of public opinion, and ruined at the next election.

The Popular Assemblies

The Roman people were organized into a number of different assemblies, each with its own rules and its own electorate. The most important were the comitia centuriata, the Centuriate Assembly, which elected the senior magistrates and voted on war and peace; the comitia tributa, the Tribal Assembly, which elected the lower magistrates and passed most ordinary laws; and the concilium plebis, the Plebeian Council, which passed laws binding on the plebeians and elected the tribunes.

These assemblies met in the open air, in the Forum or on the Campus Martius. Voting was public and was conducted by division of the assembly into its constituent groups. The rich, who were heavily over-represented in the Centuriate Assembly, usually got their way. The assemblies, in other words, were not democratic in the Greek or modern sense: they were forums in which the people could ratify or reject proposals, but they were not deliberative bodies in which the merits of a policy could be debated.

The most important check on magisterial power came from the tribuni plebis, the tribunes of the plebs. These ten officials, elected by the plebeians from 494 BCE onward, had the power of intercessio, the right to veto any act of any magistrate that they judged harmful to the plebeian order. They could also convene the Plebeian Council and propose legislation. A tribune who wished to enter the Senate could do so, but he was not a senator and could not vote. The right of veto made the tribunate one of the most powerful magistracies in the Roman state.

The Struggle of the Orders

The early Republic was dominated by the patricians, the descendants of the original senatorial families of the regal period. The plebeians, the rest of the citizen body, were excluded from the senior magistracies, from the priestly colleges, and from intermarriage with patrician families. The result was the conflict of the orders, a long political struggle that lasted from 494 to 287 BCE.

The plebeians’ first great victory was the secession of 494 BCE, in which they withdrew from Rome en masse and refused to fight until the patricians granted them the right to elect their own magistrates, the tribunes, with the power of veto. Over the next two centuries, the plebeians won further concessions: the codification of the laws in the Twelve Tables around 450 BCE; the passage of the Lex Hortensia in 287 BCE, which made plebiscites binding on all Romans; and, most importantly, the opening of the consulship to plebeians in 366 BCE with the election of Lucius Sextius.

The Lex Canuleia of 445 BCE had already abolished the ban on intermarriage, and the Lex Licinia Sextia of 367 BCE required that one of the two consuls be a plebeian. By the 3rd century BCE the patricians were a small closed caste, distinguished by ancestry and ritual privilege, while political power had passed into the hands of a broader patrician-plebeian aristocracy, the nobiles, who monopolized the consulship and the senior magistracies.

The Twelve Tables and the Birth of Roman Law

One of the most important products of the conflict of the orders was the codification of Roman law in the Twelve Tables, around 451–450 BCE. A commission of ten magistrates, the decemviri, was sent to Athens to study the laws of Solon, and on their return they drafted a code of law that was publicly displayed in the Forum on twelve bronze tablets.

The Twelve Tables are lost, but their content is known from later quotations. They covered procedures for trials, debt and inheritance, family law, property, and crimes. They were remarkable less for their content than for the fact that they existed at all: for the first time, Roman law was written down and made public, so that citizens could know their rights and magistrates could not arbitrarily invent new crimes. The Twelve Tables are traditionally considered the foundation of Roman law and, through it, of the civil-law tradition of continental Europe.

The Citizen-Farmer-Soldier: Cincinnatus and the Roman Ideal

The Republic was, in its self-image, a state of citizen-farmer-soldiers. Every Roman citizen was expected to own a small farm, work it with his own hands, and serve in the army when called. The Roman army of the early and middle Republic was a militia of landowners who marched to war in the spring, fought a campaign, and returned home in the autumn to harvest the crops. Generals came from the same class as the soldiers, served for free, and returned to their farms when their year of command was over.

The ideal of the citizen-farmer-soldier was embodied in the legend of Cincinnatus, the Roman dictator of 458 BCE. According to Livy, Cincinnatus was working his small farm when envoys from the Senate arrived to inform him that he had been named dictator to deal with a military emergency. He left the plough, defeated the enemy in sixteen days, resigned the dictatorship, and returned to his farm. For the Romans, Cincinnatus was the model of civic virtue: the citizen who served the state when called, and then relinquished power without complaint.

The ideal of Cincinnatus would prove impossible to maintain as Rome’s wars grew longer and its territory expanded. By the 2nd century BCE, Roman soldiers were serving on campaign for years at a time, and the small farms that had been the backbone of the citizen army were being absorbed into the great slave-worked latifundia of the rich. The social and military crisis that resulted would eventually destroy the Republic, in the long process described in the fall of the Roman Republic.

The Conquest of Italy

The first two centuries of the Republic were dominated by the long, slow conquest of the Italian peninsula. Rome fought a series of wars against the Latins, the Volsci, the Aequi, the Samnites, the Etruscans, and the Greek cities of southern Italy. The central event was the three Samnite Wars (343–290 BCE), in which Rome learned the hard lesson of being out-fought by a tough mountain people and emerged, eventually, the master of central and southern Italy.

By 272 BCE Rome controlled virtually the entire Italian peninsula south of the Po River. The peoples of Italy were bound to Rome by a system of bilateral treaties that gave them varying degrees of autonomy and obligation. The Latin colonies and the socii, the Italian allies, supplied the bulk of the legions that would fight the Punic Wars against Carthage. The political tension between Rome and her Italian allies would eventually erupt in the Social War of 91–88 BCE, which ended with the extension of Roman citizenship to all free inhabitants of Italy.

The Roman Army of the Republic

The Roman legion of the middle Republic was organized into the manipular system, in which the basic unit was the manipulus, a company of 120 men. Two maniples made a cohort, and ten cohorts made a legion of about 4,800 men. Each legion included three lines of heavy infantry — the hastati, the principes, and the triarii — supported by light infantry (velites) and cavalry.

For more on how the legions fought, see Roman military tactics. For the weapons and armor they carried, see Roman weapons and armor.

The manipular legion was the product of long experience and was extraordinarily flexible on the battlefield. It allowed Roman armies to absorb heavy losses and still fight effectively, and it was the instrument with which Rome defeated first Italy, then Carthage, and finally the Mediterranean world.

From Republic to Mediterranean Superpower

By the end of the 3rd century BCE, Rome had become the strongest state in the western Mediterranean. Within the next hundred and fifty years — the period of the Punic Wars against Carthage, the conquest of Greece, and the establishment of overseas provinces — it would become the unrivalled master of the entire Mediterranean basin. That transformation, and the political crisis that followed from it, is the subject of the Punic Wars and the fall of the Roman Republic.

For the broader context, see the complete history of the Roman Empire.