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.
Repulse of the Helvetii Just at this time the Helvetic invasion, which was closely interwoven with the German and had been in preparation for years, began.

That they might not make a grant of their abandoned huts to the Germans and might render their own return impossible, the Helvetii had burnt their towns and villages; and their long trains of waggons, laden with women, children, and the best part of their moveables, arrived from all sides at the Leman lake near Genava (Geneva), where they and their comrades had fixed their rendezvous for the 28th of March( 33) of this year.

According to their own reckoning the whole body consisted of 368,000 persons, of whom about a fourth part were able to bear arms.

As the mountain chain of the Jura, stretching from the Rhine to the Rhone, almost completely closed in the Helvetic country towards the west, and its narrow defiles were as ill adapted for the passage of such a caravan as they were well adapted for defence, the leaders had resolved to go round in a southerly direction, and to open up for themselves a way to the west at the point, where the Rhone has broken through the mountain-chain between the south-western and highest part of the Jura and the Savoy mountains, near the modern Fort de l'Ecluse.