Gaius Julius Caesar (?100-44 BC) was born into the senatorial aristocracy which controlled the operations of the Roman empire. Always a supporter of popular measures in the politics of the city, he became consul in 59 with the support of Pompey ('the Great'), but the alliance did not last, and the two men became first political and then military rivals.

A ten-year proconsular command in the Roman province of Gaul brought him immense wealth as well as control of a huge and devoted army, both of which factors in 49 BC enabled him to challenge Pompey for supremacy at Rome. The civil war which resulted left him, after Pompey's defeat at Pharsalus and death in Egypt, in sole control of Rome's affairs; the perpetual dictatorship and extraordinary honours which followed marked a shift in the structures of Roman politics which, despite his assassination on the Ides of March 44, was to prove permanent, and which played its part in the change from Republic to Principate.

The accounts which he wrote of his campaigns against the peoples of Gaul, Britain, and Germany (The Gallic War) and against Pompey (The Civil War) have been valued for centuries as classics of military practice and literary excellence.