How far Gaulish gold was the cause of this conversion we cannot tell.

It is in allusion to this change that he was termed the prime mover of the civil war.

His arrival in Caesar's camp is described in Book I., line 303.
He became Caesar's chief lieutenant in place of the deserter Labienus; and, as described in Book III., was sent to Sardinia and Sicily, whence he expelled the senatorial forces.

His final expedition to Africa, defeat and death, form the subject of the latter part of this book.

Mommsen describes him as a man of talent, and finds a resemblance between him and Caesar.