C. Julius Caesar's surviving output comprises seven books on the Gallic Wars (Commentarii rerum gestarum) and three on the Civil Wars. They are remarkable not only for the light which they throw on the man and on the history of the time, but as works of art.

The Commentary, as a form of literature, had a long history. Its Greek precursor was the hypomnema (or memoir), a term applied to official dispatches, minutes, administrative reports, private papers or even diaries. It was a narrative statement of facts for record purposes. It was distinct from History which was composed within a moralistic framework and with conscious literary art. Cicero, for instance, offered to submit commentarii of his consulship of 63 B.C. to L. Lucceius to turn into a history (Cicero, Fam. 5.12.10). The Romans, however, had a much greater interest in biography, as can be sensed from their funeral masks and inscriptions, from their portraiture and from the popularity of books dealing with historical examples of good and bad conduct; and Roman statesmen developed the Commentary into a factual account of their achievements which was to be published for their own self-justification and for the benefit of their descendants. We know of such works written in the generation before Caesar by M. Aemilius Scaurus, Q. Lutatius Catulus, P. Rutilius Rufus, and, above all, the dictator Sulla.

This is the literary background to the Commentaries on the Gallic Wars and on the Civil Wars. The seven books on the Gallic Wars cover the years 58 to 52 B.C., a period which witnessed Caesar's systematic subjugation of the whole of Gaul.