For the double task of keeping the neighbouring Gaul in obedience and of keeping the Germans of the right bank aloof from Gaul, the army of the lower Rhine would, even after abandoning the occupation of the region on the right of the river, have quite sufficed, and the peace without and within would not presumably have been interrupted, had not the downfall of the Julio-Claudian dynasty, and the civil or rather military war thereby called forth, exercised a momentous influence on these relations. The insurrection of the Celtic land under the leadership of Vindex was no doubt defeated by the two Germanic armies; but Nero's fall nevertheless ensued, and when the Spanish army as well as the imperial guard in Rome appointed a successor to him, the armies of the Rhine did the same; and in the beginning of the year 69 the greater portion of these troops crossed the Alps to settle the point on the battle-fields of Italy, whether its ruler was to be called Marcus or Aulus. In May of the same year the new emperor Vitellius followed, after arms had decided in his favour, accompanied by the remainder of the good soldiers inured to war. The blanks in the garrisons of the Rhine were no doubt filled up for the exigency by recruits hastily levied in Gaul; but the whole land knew that they were not the old legions, and it soon became apparent that these were not coming back. If the new ruler had had in his power the army that placed him on the throne, at least a portion of them must have returned to the Rhine immediately after the defeat of Otho in April; but the insubordination of the soldiers still more than the new complication which soon set in with the proclamation of Vespasian as emperor in the East, retained the German legions in Italy. [Sidenote: Preparations for the insurrection.]