C. Julius Caesar, Gallic War

Caesar was now reported to have departed from Gergovia ; intelligence was likewise brought to them concerning the revolt of the Aedui, and a successful rising in Gaul; and that Caesar, having been prevented from prosecuting his journey and crossing the Loire , and having been compelled by the want of corn, had marched hastily to the province. But the Bellovaci, who had been previously disaffected of themselves, on learning the revolt of the Aedui, began to assemble forces and openly to prepare for war. Then Labienus, as the change in affairs was so great, thought that he must adopt a very different system from what he had previously intended, and he did not now think of making any new acquisitions, or of provoking the enemy to an action; but that he might bring back his army safe to Agendicum. For, on one side, the Bellovaci, a state which held the highest reputation for prowess in Gaul, were pressing on him; and Camulogenus, with a disciplined and well-equipped army, held the other side; moreover, a very great river separated and cut off the legions from the garrison and baggage. He saw that, in consequence of such great difficulties being thrown in his way, he must seek aid from his own energy of disposition.