The Roman expansion in Italy covers a series of conflicts in which Rome grew from being a small Italian city-state to be the ruler of the Italian peninsula. Roman tradition attributes to the Roman kings the first war against the Sabines and the first conquests around the Alban Hills and down to the coast of Latium. The birth of the Roman Republic after the overthrow of the Etruscan monarch of Rome in 509 BC began a series of major wars between the Romans and the Etruscans. In 390 BC, Gauls from the north of Italy sacked Rome. In the second half of the 4th century BC Rome clashed repeatedly with the Samnites, a powerful tribal coalition of the Apennine region. By the end of these wars, Rome had become the most powerful state in central Italy and began to expand to the north and to the south. The last threat to Roman hegemony came during the Pyrrhic war (280-275 BC) when Tarentum enlisted the aid of the Greek king Pyrrhus of Epirus to campaign in the South of Italy. Resistance in Etruria was finally crushed in 265-264 BC, the same year the First Punic War began and brought Roman forces outside of the peninsula for the first time.