Pyrrhus of Epirus was a Hellenistic king of Epirus and a renowned military commander who reigned from approximately 319/318 to 272 BCE. A second cousin of Alexander the Great, he secured his throne in 297 BCE and embarked on ambitious campaigns to build a western empire. This expansion led to the Pyrrhic War against Rome from 280 to 275 BCE, a conflict famed for its costly victories.

His later campaign in the Peloponnese ended with his death in street fighting at Argos in 272 BCE. His life was documented by the historian Hieronymus of Cardia and later by Plutarch. Pyrrhus's only known work is his now-lost Memoirs or Commentaries. Plutarch cites this autobiographical text as a source for diplomatic details in his own biography of the king.

Pyrrhus is historically significant for his major military confrontation with the expanding Roman Republic, which highlighted the tactical limitations of the Hellenistic phalanx against the Roman legion. His career exemplifies the volatile nature of Hellenistic kingship, and his name endures in the concept of the "Pyrrhic victory." His lost memoirs represent a rare autobiographical source by a Hellenistic monarch.