By this language, Cæsar wished to show that he did not violate the law, enacted a year before under his consulate, which forbade the governors to leave their provinces without an order of the Senate. He purposely appealed to an old decree, which gave unlimited powers to the governor of Gaul, a province the importance of which had always required exceptional laws.[206] The reply of Ariovistus was equally proud:-- “Cæsar ought to know as well as he the right of the conqueror: he admits no interference in the treatment reserved for the vanquished; he has himself causes of complaint against the proconsul, whose presence diminishes his revenues; he will not restore the hostages to the Ædui; the title of brothers and allies of the Roman people will be of little service to them. He cares little for threats. No one has ever braved Ariovistus with impunity. Let anybody attack him, and he will learn the valour of a people which, for fourteen years, has never sought shelter under a roof.”[207] [Sidenote: March of Cæsar upon Besançon.] III. This arrogant reply, and news calculated to give alarm, hastened Cæsar’s decision. In fact, on one side the Ædui complained to him of the devastation of their country by the Harudes; and, on the other, the Treviri announced that the hundred cantons of the Suevi were preparing to cross the Rhine.[208] Cæsar, wishing to prevent the junction of these new bands with the old troops of Ariovistus, hastened the collecting of provisions, and advanced against the Germans by forced marches. The negotiations having probably lasted during the month of July, it was now the beginning of August. Starting from the neighbourhood of Tonnerre, where we have supposed he was encamped, Cæsar followed the road subsequently replaced by a Roman way of which vestiges are still found, and which, passing by Tanlay, Gland, Laignes, Etrochey, and Dancevoir, led to Langres.[209] (_See Plate 4._) After three long days’ marches, on his arrival towards Arc-en-Barrois, he learnt that Ariovistus was moving with all his troops to seize Besançon, the most considerable place in Sequania, and that he had already advanced three days’ march beyond his territory. Cæsar considered it a matter of urgency to anticipate him, for this place was abundantly provided with everything necessary for an army. Instead of continuing his march towards the Rhine, by way of Vesoul, Lure, and Belfort, he advanced, day and night, by forced marches, towards Besançon, obtained possession of it, and placed a garrison there.[210]