de bello gallico, 5.46

Caesar, the letters having been received about the eleventh hour of the day, immediately sends a messenger among the Bellovaci, to Marcus Crassus, quaestor there, whose winter-quarters were twenty-five miles distant from him; he orders the legion to set out in the middle of the night and come to him quickly. Crassus set out with the messenger. He sends another to Gaius Fabius, the lieutenant, to lead his legion into the territories of the Atrebates, to which he knew his march must be made. He writes to Labienus to come with his legion to the territory of the Nervii, if he could act for the advantage of the republic. He does not think that the remaining portion of the army, because it was somewhat farther distant, should be waited for; he gathers about 400 horsemen from the nearest winter-quarters.