Battle of the Thur (fought before the new moon, which took place on the 18th of September) September 10. CHAPTER V. WAR AGAINST THE BELGÆ. (Year of Rome 697.) (BOOK II. OF THE “COMMENTARIES.”) [Sidenote: League of the Belgæ. Cæsar advances from Besançon to the Aisne.] I. The brilliant successes gained by Cæsar over the Helvetii and the Germans had delivered the Republic from an immense danger, but at the same time they had roused the distrust and jealousy of most of the nations of Gaul. These conceived fears for their independence, which were further increased by the presence of the Roman army in Sequania. The irritation was very great among the Belgæ. They feared that their turn to be attacked would come when Celtic Gaul was once reduced to peace. Besides, they were excited by influential men who understood that, under Roman domination, they would have less chance of obtaining possession of the supreme power. The different tribes of Belgic Gaul entered into a formidable league, and reciprocally exchanged hostages. Cæsar learnt these events in the Cisalpine province, through public rumour and the letters of Labienus. Alarmed at the news, he raised two legions in Italy, the 13th and 14th, and, in the beginning of spring,[238] sent them into Gaul, under the command of the lieutenant Q. Pedius.[239] It is probable that these troops, to reach Sequania promptly, crossed the Great St. Bernard, for Strabo relates that one of the three routes which led from Italy into Gaul passed by Mount Pœrinus (_Great St. Bernard_), after having traversed the country of the Salassi (_Valley of Aosta_), and that this latter people offered at first to assist Cæsar’s troops in their passage by levelling the roads and throwing bridges across the torrents; but that, suddenly changing their tone, they had rolled masses of rock down upon them and pillaged their baggage. It was no doubt in the sequel of this defection that, towards the end of the year 697, Cæsar, as we shall see farther on, sent Galba into the Valais, to take vengeance on the mountaineers for their perfidious conduct and to open a safe communication with Italy.[240] As soon as forage was abundant, he rejoined his legions in person, probably at Besançon, since, as we have seen, they had been placed in winter quarters in Sequania. He charged the Senones and the other Celts who bordered upon Belgic Gaul to watch what was doing there and inform him of it. Their reports were unanimous: troops were being raised, and an army was assembling. Cæsar then decided upon immediately entering into campaign.