The Roman Republic had a fairly complex system of government and representation, but it was one that would last about 500 years and preside over the vast expansion of Roman power. An assembly, called the Centuriate Assembly, was elected by the citizens and created laws. Each year, the assembly elected two executives called consuls to oversee the laws and ensure their enforcement. The consuls had almost unlimited power, known as imperium, including the right to inflict the death penalty on law-breakers, and they were preceded everywhere by twelve bodyguards called lictors. Consular authority was, however, limited by the fact that terms were only a year long and each consul was expected to hold the other in check if necessary. Under the consuls there was the senate, essentially a large body of aristocratic administrators who controlled state finances. The whole system was tied closely to the priesthoods of the Roman gods, who performed divinations and blessings on behalf of the city. While the Romans were deeply suspicious of individuals who seemed to be trying to take power themselves, several influential families worked behind the scenes to ensure that they could control voting blocks in the Centuriate Assembly and the Senate.
When Rome faced a major crisis, the Centuriate Assembly could vote to appoint a dictator, a single man vested with the full power of imperium. Symbolically, all twenty-four of the lictors would accompany the dictator, who was supposed to use his almost-unlimited power to save Rome from whatever threatened it, then step down and return things to normal. While the office of dictator could have easily led to an attempted takeover, for hundreds of years very few dictators abused their powers and instead respected the temporary nature of Roman dictatorship itself.
The rich were referred to as patricians, families with ancient roots in Rome who occupied most of the positions of the senate and the judiciary in the city. There were about one hundred patrician families, descending from the men Romulus had, allegedly, appointed to the first senate. They were allied with other rich and powerful people, owners of large tracts of land, in trying to hold in check the plebeians, Roman citizens not from patrician backgrounds.
While the senate began as an advisory body, it later wrested real law-making power from the consuls (who were, after all, almost always drawn from its members). By 133 BCE, the senate proposed legislation and could veto the legislation of the consuls. An even more important power was its ability to designate funds for war and public building, giving it enormous power over what the Roman government actually did, since the senate could simply cut off funding to projects it disagreed with.
The Centuriate Assembly was divided into five different classes based on wealth (a system that ensured that the wealthy could always outvote the poorer). The wealthiest class consisted of the equestrians, so named because they could afford horses and thus form the Roman cavalry; the equestrian class would go on to be a leading power bloc in Roman history well into the Imperial period. The Centuriate Assembly voted on the consuls each year, declared war and peace, and acted as a court of appeal in legal cases involving the death penalty. It could also propose legislation, but the senate had to approve it for it to become law.