A system without a king
According to Roman tradition, the last king was expelled in 509 BCE, and the city then chose to be governed by annually elected officials rather than a monarch. The details of that story are legendary, and the republic probably developed over a longer period. But the basic idea is clear and was central to Roman self-image: power should be shared, limited in time and answerable to others.
The republic never had a single written constitution. It was a collection of laws, customs and precedents that Romans called the mos maiorum, or ancestral way. Because it grew by accretion, it was flexible, and also open to disputes about what the rules actually were. The Greek historian Polybius, writing in the second century BCE, described it as a mixture of monarchy (the consuls), aristocracy (the senate) and democracy (the people). His picture is influential but idealised.
Magistrates
Government was carried out by magistrates, who were elected, held office for a limited period, and usually served with colleagues who could restrain them.
- Consuls. Two were elected each year. They commanded armies, presided over the senate and the assemblies, and held the highest authority. Each could block the other’s actions.
- Praetors. These officials mainly administered justice, and their annual announcements of how they would apply the law shaped legal development. Their role is linked to the topic of Roman civil law. Praetors could also command armies and govern provinces.
- Quaestors. Junior officials who dealt with public finance, and whose election gave entry to the senate.
- Aediles. They supervised markets, public buildings and festivals.
- Censors. Elected about every five years, they took the census, assigned citizens to classes and revised the list of senators.
- Tribunes of the plebs. Ten officials who protected ordinary citizens and could veto laws and the actions of other magistrates.
In emergencies the senate could call for a dictator, who held supreme authority for up to six months. This was a rarely used device in the early republic, and later it fell out of use until it was revived in the last century BCE in a different form.
Politicians usually followed a sequence of offices, later called the cursus honorum, with minimum ages and gaps between posts. Competition for office was fierce, and it was expensive, because candidates were expected to fund games and public works.
The senate
The senate was not elected. It consisted largely of former magistrates, who served for life unless removed by the censors. Its membership was generally about three hundred in the earlier republic, and it was enlarged under Sulla in the first century BCE.
Formally, the senate only advised. It issued decrees, called senatus consulta, which magistrates normally followed. In practice, it controlled finances, foreign policy, the assignment of provinces and the management of wars, so its influence was great. The reason was continuity: magistrates came and went each year, while the senate and its experienced members remained. That continuity made the Roman Senate the centre of political life, and its prestige was a result of habit and respect as much as law.
The assemblies
Citizens voted in several assemblies, each organised differently. The assembly arranged by military-style groups, the comitia centuriata, elected consuls and praetors and decided on war. The tribal assemblies elected junior magistrates and passed many laws. The plebeian assembly, open only to plebeians, elected tribunes and passed measures known as plebiscites.
Voting was weighted. In the assembly of centuries, for example, richer citizens were grouped in a way that gave them more influence, so that the votes of the wealthy could decide the outcome before the poorest were consulted. Citizens also had to be in Rome to vote, which disadvantaged those living far away as the citizen body spread across Italy. Compared with the Athenian democracy, which gave all male citizens an equal vote in a single assembly, the Roman system gave the people a real but limited role.
The conflict of the orders
In the early republic the patricians, an hereditary aristocracy, held most offices, and the plebeians, the rest of the citizens, struggled for a share. According to tradition, the plebeians withdrew from the city in 494 BCE until they were granted their own officials, the tribunes. This struggle, often called the Conflict of the Orders, lasted for roughly two centuries. It produced the Twelve Tables, an early written body of law dated traditionally to about 450 BCE, and later measures opened the consulship and other offices to plebeians. In 287 BCE a law is generally reported as making plebiscites binding on all citizens.
The result was not a democracy but a broader ruling class, in which wealthy plebeian families joined the old patricians in a mixed nobility.
Tensions and breakdown
Several strains grew over time. Conquest brought wealth and also created pressures: soldiers needed land, the rich acquired large estates, and enslaved labour became widespread, which touched on questions of Roman slavery. Italian allies who fought in Rome’s wars wanted citizenship, and they won it after a major war in the early first century BCE.
Reformers such as the Gracchi brothers, Tiberius in 133 BCE and Gaius in 123-122 BCE, tried to redistribute public land and were killed in political violence. This marked a turning point, as it showed that disputes could be settled by force. Later commanders such as Marius, Sulla, Pompey and Caesar raised armies that were loyal more to them than to the state, creating the pattern of civil war generals that eventually ended the republic. The system had been designed for a city-state, and it struggled to govern a Mediterranean empire.
What it left behind
The republic ended in practice with the victory of Octavian, and the system that followed, described in the Augustan principate, kept many republican offices while concentrating power. Roman ideas of law, office-holding and shared authority later influenced political thought far beyond Rome, although how directly is debated.