The Pyrrhic War (280–275 BC) was a complex series of battles and shifting political alliances among the Greeks (specifically Epirus, Macedonia, and the city states of Magna Graecia), Romans, the Italian peoples (primarily the Samnites and the Etruscans), and the Carthaginians.
The Pyrrhic War initially started as a minor conflict between Rome and the city of Tarentum over a naval treaty violation by one of the Roman consuls. Tarentum had, however, lent aid to the Greek ruler Pyrrhus of Epirus in his conflict with Corcyra, and requested military aid from Epirus. Pyrrhus honored his obligation to Tarentum and joined the complex series of conflicts involving Tarentum, the Romans, Samnites, Etruscans, and Thurii (as well as other cities of Magna Graecia). To further complicate historical analysis of the conflict, Pyrrhus also involved himself in the internal political conflicts of Sicily, as well as the Sicilian struggle against Carthaginian dominance.