Pyrrhus

Pyrrhus or Pyrrhos (; 319–272 BC) was a Greek king and statesman of the Hellenistic period. His life was lived in the rather confused times following the death of Alexander the Great. Alexander's successors, known as the Diadochi, were continually at war with each other over bits and pieces of Alexander's vast Empire.
Pyrrhus was king of the Greek Molossian tribe (from ca. 297 BC). Later he became King of Epirus (306302, 297–272 BC) and Macedon (288–284, 273–272 BC). 
He was one of the strongest opponents of early Rome. However, some of his battles, though successful, cost him heavy losses. From this the term "Pyrrhic victory" was coined. A Pyrrhic victory is a victory gained at too great a cost. Pyrrhus is the subject of one of Plutarch's Parallel Lives.