Roman Republic

After 500 BC, Rome joined with the Latin cities in defence against incursions by the Sabines. Winning the Battle of Lake Regillus in 493 BC, Rome established again the supremacy over the Latin countries it had lost after the fall of the monarchy. After a lengthy series of struggles, this supremacy became fixed in 393, when the Romans finally subdued the Volsci and Aequi. In 394 BC, they also conquered the menacing Etruscan neighbour of Veii. The Etruscan power was now limited to Etruria itself, and Rome was the dominant city in Latium.
Also a formal treaty with the city of Carthage is reported to have been made in the end of the 6th century BC, which defined the spheres of influence of each city and regulated the trade between them.


Chart Showing the Checks and Balances of the Roman Constitution.
At the same time, Heraclides states that 4th century Rome is a Greek city.[22]
Rome's early enemies were the neighbouring hill tribes of the Volscians, the Aequi, and of course the Etruscans. As years passed and military successes increased Roman territory, new adversaries appeared. The fiercest were the Gauls, a loose collective of peoples who controlled much of Northern Europe including what is modern North and Central-East Italy.
In 387 BC, Rome was sacked and burned by the Senones coming from eastern Italy and led by Brennus, who had successfully defeated the Roman army at the Battle of the Allia in Etruria. Multiple contemporary records suggest that the Senones hoped to punish Rome for violating its diplomatic neutrality in Etruria. The Senones marched 130 kilometres (81 mi) to Rome without harming the surrounding countryside; once sacked, the Senones withdrew from Rome.[23] Brennus was defeated by the dictator Furius Camillus at Tusculum soon afterwards.[24][25]
After that, Rome hastily rebuilt its buildings and went on the offensive, conquering the Etruscans and seizing territory from the Gauls in the north. After 345 BC, Rome pushed south against other Latins. Their main enemy in this quadrant were the fierce Samnites, who heavily defeated the legions in 321 BC at the Battle of Caudine Forks. In spite of these and other temporary setbacks, the Romans advanced steadily. By 290 BC, Rome controlled over half of the Italian peninsula. In the 3rd century BC, Rome brought the Greek poleis in the south under its control as well.[2