Roman Republic: The rise and fall of ancient Rome's government

The Roman Republic was a form of government in Rome that lasted from around 509 B.C. to 27 B.C. According to ancient Roman writers, the Roman Republic emerged in 509 B.C., after the last king of Rome was deposed. Modern-day historians often consider the official end of the Roman Republic to be 27 B.C., which was the year that Octavian — who had risen to become the ruler of Rome — was given the title "Augustus" (a title that means revered one) by the Roman senate.

The Roman Republic was a period of territorial expansion presided over by a government that was designed to represent both the wealthy and poor citizens of ancient Rome. While this system somewhat benefited Roman citizens, it often resulted in harsh treatment for anyone who was not a citizen of Rome.
Surviving historical and archaeological remains indicate that it took centuries for Rome to conquer all of Italy. Rome gradually took over cities and territories in Italy, employing a variety of tactics, Bringmann noted. These tactics would gradually see Rome take control of much of the Italian mainland during the fourth and third centuries B.C.

The Roman Republic used a complex system that incorporated a senate, consuls, magistrates, tribunes, and at times a dictator and other public officials. This system changed over time, incorporating the interests of both the patricians (the families of Rome that were from a noble, elite, background) and the plebeians, Roman citizens who were not nobles and often came from poorer backgrounds.

For voting purposes, citizens were often divided into a system of centuries and tribes, a person's wealth or geographic location sometimes having a bearing on which century and tribe they belonged to, wrote Bringmann. As time went on, and Roman territory expanded, the republic system broke down and sometimes led to two or more strongmen fighting for control of Rome.

In the period after 146 B.C., Rome's territory continued to grow, but the city's republic government crumbled. Strongmen such as Sulla, Pompey, Crassus, Julius Caesar, Mark Antony and Octavian vied for control of Rome. Civil wars and violent unrest occurred during this time. The Roman historian Sallust (lived 85 B.C. to 35 B.C.) believed that the increasing amount of wealth in Rome, generated partly through Rome's conquered territories, helped bring about the rise of these strongmen and the fall of the Roman Republic. "The lust for money first, then for power, grew upon them; these were, I may say, the root of all evils," wrote Sallust (translation by John Carew Rolfe).

large (long?) article at:
https://www.livescience.com/roman-republic