Gnaeus Pompeius Magnus, also known as Pompey IPA-en?p?mpi or Pompey the Great (Classical Latin abbreviation: CN�POMPEIVS�CN�F�SEX�N�MAGNVS) (September 29, 106 BC – September 29, 48 BC), was a military and political leader of the late Roman Republic. He came from a wealthy Italian (Italy) provincial background, and established himself in the ranks of Roman nobility (Patrician (ancient Rome)) by successful leadership in several campaigns. Sulla addressed him by the cognomen Magnus (List of Roman cognomina#M) (the Great) and he was awarded three triumphs (Roman triumph).

Pompey joined his rival Marcus Licinius Crassus and his ally and father-in-law Julius Caesar in the military-political alliance known as the First Triumvirate. After the deaths of Crassus and Julia (Julia (daughter of Julius Caesar)), Pompeys wife and Caesars daughter, Pompey and Caesar contended the leadership of the Roman state in a civil war (Caesars civil war). Pompey sided with the optimates, the conservative and aristocratic majority of the Roman Senate. When Caesar defeated him at the battle of Pharsalus he sought refuge in Egypt, where he was assassinated. His career and defeat are significant in Romes subsequent transformation from Republic (Roman Republic) to Principate and Empire (Roman Empire).