After this fearful disaster the rest of the emigrants, to the number of 110,000, continued their march through Gaul, but lacking both food and capable leaders, and being moreover ill-used by the Gauls, they sent to Cæsar for help. He demanded hostages, and ordered them to return home and rebuild their towns and villages. And, further, he supplied them with food for the journey, and requested the Allobroges to do the same when the Helvetians should arrive in their province. Cæsar admits that this apparent generosity on his part was dictated not by compassion, but by policy. It was to his interest that these barbarians should re-occupy Helvetia, because they would keep watch on the Rhine, and prevent the irruption of the Germans into the country. In their condition now, he calls the Helvetians ASSOCIATES (_foederati_), and not SUBJECTS, and leaves them their own constitution, and, to some extent, their freedom. But they did not relish this forced friendship, which was indeed more like bondage; and when the Celts of Gaul rose in revolt under the noble and beloved Vercingetorix, who had been a friend of Cæsar, they joined their brethren (52 B.C.), and were again vanquished. On the defeat of the Helvetians at Bibracte followed that of the Valisians, in 57 B.C. To establish a direct communication between Central Gaul and Italy, Cæsar took those same measures which Napoleon I. employed long afterwards; he conquered the Valais (by his lieutenant Galba), that he might secure the passage of the Great St. Bernard. A splendid road was formed over Mount Poeninus, and a temple erected to Jupiter Poeninus, where the traveller left votive tablets as a thanksgiving offering after a fortunate ascent. The subjugation of Rhætia was delayed for more than a generation. To guard the empire against the Eastern hordes; against the mountain robbers of Graubünden and the Tyrol, who descended into the valleys of the Po, ravaging the country as far as Milan, and no doubt liberally paying back in their own coin, the Romans who had made from time to time such havoc in the Alpine homes--to guard against these, and the wild Vindelicians of Bavaria, Augustus sent the two imperial princes to reduce them to subjection. Drusus marched into the Tyrol, whilst Tiberius advanced on Lake Constance, where even the Rhætian women engaged in the conflict, and, in default of missiles, hurled their sucking children into the face of the conquerors, through sheer exasperation. Their savage courage availed them nothing, however; the incursions from the East were repressed; and once the Rhætians were overcome, they became the most useful of auxiliaries to the Roman army. Horace's ode to Drusus alludes to the Rhætian campaign.