The war was prolonged for some years with varying success; on the whole the results were unfavourable to the Haedui. Their leader Eporedorix at length called out their whole clients, and marched forth with an enormous superiority of force against the Germans. These obstinately refused battle, and kept themselves under cover of morasses and forests. It was not till the clans, weary of waiting, began to break up and disperse, that the Germans appeared in the open field, and then Ariovistus compelled a battle at Admagetobriga, in which the flower of the cavalry of the Haedui were left on the field. The Haedui, forced by this defeat to conclude peace on the terms which the victor proposed, were obliged to renounce the hegemony, and to consent with their whole adherents to become clients of the Sequani; they had to bind themselves to pay tribute to the Sequani or rather to Ariovistus, and to furnish the children of their principal nobles as hostages; and lastly they had to swear that they would never demand back these hostages nor invoke the intervention of the Romans.

This peace was concluded apparently about 693[29]. Honour and advantage enjoined the Romans to come forward in opposition to it; the noble Haeduan Divitiacus, the head of the Roman party in his clan, and for that reason now banished by his countrymen, went in person to Rome to solicit their intervention. A still more serious warning was the insurrection of the Allobroges in 693[30] - the neighbours of the Sequani - which was beyond doubt connected with these events. In reality orders were issued to the Gallic governors to assist the Haedui; they talked of sending consuls and consular armies over the Alps; but the senate, to whose decision these affairs primarily fell, at length here also crowned great words with little deeds. The insurrection of the Allobroges was suppressed by arms, but nothing was done for the Haedui; on the contrary, Ariovistus was even enrolled in 695 in the list of kings friendly with the Romans[31].

The German warrior-prince naturally took this as a renunciation by the Romans of the Celtic land which they had not occupied; he accordingly took up his abode there, and began to establish a German principality on Gallic soil. It was his intention that the numerous bands which he had brought with him, and the still more numerous bands that afterwards followed at his call from home - it was reckoned that up to 696 some 120,000 Germans had crossed the Rhine - this whole mighty immigration of the German nation, which poured through the once opened sluices like a stream over the beautiful west, should become settled there and form a basis on which he might build his dominion over Gaul. The extent of the German settlements which he called into existence on the left bank of the Rhine cannot be determined; beyond doubt it was great, and his projects were far greater still. The Celts were treated by him as a wholly subjugated nation, and no distinction was made between the several cantons. Even the Sequani, as whose hired commander-in-chief he had crossed the Rhine, were obliged, as if they were vanquished enemies, to cede to him for his people a third of their territory - presumably upper Alsace afterwards inhabited by the Triboci - where Ariovistus permanently settled with his followers; nay, as if this were not enough, a second third was afterwards demanded of them for the Harudes who arrived subsequently. Ariovistus seemed as if he wished to take up in Gaul the part of Philip of Macedonia, and to play the master over the Celts who were friendly to the Germans no less than over those who adhered to the Romans.

Spread of the Helvetian Invasion to the Interior of Gaul The appearance of the energetic German prince in so dangerous proximity, which could not but in itself excite the most serious apprehension in the Romans, appeared still more threatening, inasmuch as it stood by no means alone. The Usipetes and Tencteri settled on the right bank of the Rhine, weary of the incessant devastation of their territory by the overbearing Suebian tribes, had, the year before Caesar arrived in Gaul (695), set out from their previous abodes to seek others at the mouth of the Rhine.

They had already taken away from the Menapii there the portion of their territory situated on the right bank, and it might be foreseen that they would make the attempt to establish themselves also on the left. Suebian bands, moreover, assembled between Cologne and Mayence, and threatened to appear as uninvited guests in the opposite Celtic canton of the Treveri. Lastly, the territory of the most easterly clan of the Celts, the warlike and numerous Helvetii, was visited with growing frequency by the Germans, so that the Helvetii, who perhaps even apart from this were suffering from over-population through the reflux of their settlers from the territory which they had lost to the north of the Rhine, and besides were liable to be completely isolated from their kinsmen by the settlement of Ariovistus in the territory of the Sequani, conceived the desperate resolution of voluntarily evacuating the territory hitherto in their possession to the Germans, and acquiring larger and more fertile abodes to the west of the Jura, along with, if possible, the hegemony in the interior of Gaul - a plan which some of their districts had already formed and attempted to execute during the Cimbrian invasion[32].

the Rauraci whose territory (Basle and southern Alsace) was similarly threatened, the remains, moreover, of the Boii who had already at an earlier period been compelled by the Germans to forsake their homes and were now unsettled wanderers, and other smaller tribes, made common cause with the Helvetii. As early as 693 their flying parties came over the Jura and even as far as the Roman province; their departure itself could not be much longer delayed; inevitably German settlers would then advance into the important region between the lakes of Constance and Geneva forsaken by its defenders. From the sources of the Rhine to the Atlantic Ocean the German tribes were in motion; the whole line of the Rhine was threatened by them; it was a moment like that when the Alamanni and the Franks threw themselves on the falling empire of the Caesars; and even now there seemed on the eve of being carried into effect against the Celts that very movement which was successful five hundred years afterwards against the Romans.

Under these circumstances the new governor Gaius Caesar arrived in the spring of 696 in Narbonese Gaul, which had been added by decree of the senate to his original province embracing Cisalpine Gaul along with Istria and Dalmatia. His office, which was committed to him first for five years (to the end of 700), then in 699 for five more (to the end of 705), gave him the right to nominate ten lieutenants of propraetorian rank, and (at least according to his own interpretation) to fill up his legions, or even to form new ones at his discretion out of the burgess-population - who were especially numerous in Cisalpine Gaul - of the territory under his sway. The army, which he received in the two provinces, consisted, as regards infantry of the line, of four legions trained and inured to war, the seventh, eighth, ninth, and tenth, or at the utmost 24,000 men, to which fell to be added, as usual, the contingents of the subjects. The cavalry and light-armed troops, moreover, were represented by horsemen from Spain, and by Numidian, Cretan, and Balearic archers and slingers. The staff of Caesar - the elite of the democracy of the capital - contained, along with not a few useless young men of rank, some able officers, such as Publius Crassus the younger son of the old political ally of Caesar, and Titus Labienus, who followed the chief of the democracy as a faithful adjutant from the Forum to the battle-field. Caesar had not received definite instructions; to one who was discerning and courageous these were implied in the circumstances with which he had to deal. Here too the negligence of the senate had to be retrieved, and first of all the stream of migration of the German peoples had to be checked.