C. Julius Caesar, Gallic War

After this a decree was passed by the senate, that one legion should be sent by Pompey, and another by Caesar, to the Parthian war. But these two legions were evidently drawn from Caesar alone. For the first legion which Pompey sent to Caesar, he gave Caesar, as if it belonged to himself, though it was levied in Caesar's province. Caesar, however, though no one could doubt the design of his enemies, sent the legion back to Cneius Pompey, and in compliance with the decree of the senate, ordered the fifteenth, belonging to himself, and which was quartered in Cisalpine Gaul, to be delivered up. In its room he sent the thirteenth into Italy, to protect the garrisons from which he had drafted the fifteenth. He disposed his army in winter quarters, placed Caius Trebonius, with four legions among the Belgae, and detached Caius Fabius, with four more, to the Aedui; for he thought that Gaul would be most secure, if the Belgae, a people of the greatest valor, and the Aedui, who possessed the most powerful influence, were kept in awe by his armies.