The Helvetii, prevented by this passage of the river on the part of the Roman army from continuing their march westward, turned in a northerly direction, doubtless under the supposition that Caesar would not venture to follow them far into the interior of Gaul, and with the intention, if he should desist from following them, of turning again toward their proper destination.

For fifteen days the Roman army marched behind that of the enemy at a distance of about four miles, clinging to its rear, and hoping for an advantageous opportunity of assailing the Helvetic host under conditions favourable to victory, and destroying it.

But this moment came not: unwieldy as was the march of the Helvetic caravan, the leaders knew how to guard against a surprise, and appeared to be copiously provided with supplies as well as most accurately informed by their spies of every event in the Roman camp.

On the other hand the Romans began to suffer from want of necessaries, especially when the Helvetii removed from the Saone and the means of river-transport ceased.

The non-arrival of the supplies promised by the Haedui, from which this embarrassment primarily arose, excited the more suspicion, as both armies were still moving about in their territory.