Explanation: The Greek king Pyrrhus of Epirus famously fought the Roman Republic in a number of battles, most of which he won. However, his victories were not sustainable - his forces he could transport to Italy were limited, while the Romans had a seemingly inexhaustible supply of manpower. Pyrrhus supposedly stated after winning against the Romans, "One more such victory and we shall be undone", referring to his own losses incurred in the battle. From this, we get the term 'Pyrrhic Victory', meaning a victory not worth the cost to achieve it. Pyrrhus eventually was forced to withdraw from Italy, despite his battlefield successes (or 'successes').
Pyrrhus of Epirus would later be killed in Greece during street fighting, a soldier's mother tossing a roof tile onto his skull to defend her son, killing Pyrrhus.