The Roman Republic ran from 509 BC to 27 BC
Tradition says Romans expelled Tarquin the Proud in 509 BC and built a res publica that only ended when Actium's aftermath made Augustus emperor in 27 BC. Between those poles lay near-constant war abroad and a long struggle between patricians and plebs at home.
The Roman Republic names classical Rome from the kingdom's overthrow, traditionally 509 BC, to the empire's start in 27 BC after the War of Actium. Society mixed Latin, Etruscan, Sabine, Oscan, and Greek elements visible in religion and pantheon. Politics matured alongside Greek experiments with direct democracy, yet republican Rome knew little peace: Latin and Etruscan neighbors, then Gauls who sacked the city around 387 BC, preceded conquest of most of Italy and overseas wars that remade the Mediterranean.
The Conflict of the Orders pitted a closed patrician elite against the more numerous plebs and resolved toward political equality by the fourth century BC. From 133 BC the late Republic saw bitter domestic strife. Kings had been elected for life by senators; the last, Tarquin the Proud, was expelled in tradition because his son Sextus raped Lucretia. Tarquin's restoration bids—including a conspiracy involving Brutus's sons—failed through wars with Veii, Tarquinii, and Clusium. Between 376 and 367 BC the plebeian tribunes Gaius Licinius Stolo and Lucius Sextius Lateranus pushed through laws opening the consulship to plebeians, and in 356 BC Gaius Marcius Rutilus became the first plebeian dictator.
Early republican campaigns beat Sabines and Latin rivals at Lake Regillus in 496 BC, Ariccia in 495 BC, and later battles. About fifty patrician gentes monopolized magistracies, priesthoods, and senior commands after Tarquin's fall. Over centuries that oligarchy yielded offices and law to plebeian pressure, even as expansion made Rome Mediterranean master—and as generals with private armies finally broke the republican settlement Augustus replaced with imperial rule. Even the famous Gallic disaster is shaky ground: Romans were routed at the Allia, about 11 Roman miles north of the city, but archaeologists find no destruction layer, so any sack was probably light.
Source: Roman Republic
