The maintenance of supplies required special attention, and at first the 8th Brigade had to be left behind to secure the all-important railway-line Tonnerre—Nuits—Châtillon, until connections could be established by way of Epinal.
On the very first day's march the advanced guard of the VIIth Corps had a fight before Langres. A force from the garrison of 15,000 men was driven in on the fortress with the loss of a flag, and a detachment had to be left behind in observation of the place. Under cover of it the VIIth Corps marched past the fortress next day, while the IInd advanced to the Ignon Brook.
The weather changed during the night of the 15th. As a change from fourteen degrees of frost there came storm and rain. The water lay on the frozen roads, and it was with the greatest difficulty that the VIIth Corps reached Prauthoy, and the IInd Moloy, closing in to the left.
On the 18th the left wing advanced South-East on Frettes and Champlitte, the right assembled at Is sur Tille, and its advanced guard, after a march of thirty-one miles, reached the bridges at Gray. On the flank and rear of the Corps there had been some trivial fighting, but the cruel march across the mountains had been accomplished, and the cultivated valley of the Saône was reached.
General von Manteuffel had already received news of the satisfactory course of the first day's fighting on the Lisaine. Later telegrams from General von Werder reported that the French Army of the East would probably be obliged to retire under difficulties, and the German commander at once determined to cut off its retreat by advancing to the Doubs below Besançon.
The defeated French army was still numerically greatly superior to the German force. The troops had to be again called upon for severe exertions. They were required once more to cross a thinly-populated mountainous region, where it would be a matter of great difficulty to procure food and the shelter needful during the bitter winter nights. Strong hostile forces had to be left in the rear at Langres, Dijon, and Auxonne, and that under very insufficient observation. However, in spite of every obstacle the advance in this new direction was begun on the 19th.
The first difficulty would have been the crossing of the Saône, here very deep and about sixty-six yards wide, and full of drifting ice, had not the advanced guard of the IInd Corps found Gray abandoned by the French and both the bridges uninjured; whereupon it occupied the town. The head of the VIIth Corps crossed the river by the intact railway-bridge at Savayeux, and by a pontoon bridge thrown across by the pioneers higher up.
On the following day both Corps advanced in a southerly direction, the VIIth to Gy, the IInd to Pesmes. Here the latter also now crossed the Ognon after driving off by artillery fire a French detachment which tried to oppose the construction of the bridges.
On the 21st, at half past two, the advanced guard of the IInd Corps found Dôle occupied by the enemy. General von Koblinski (commanding 5th Infantry Brigade) attacked at once. In spite of a violent street-fight in which the townspeople took part, the Grenadiers of the 2nd Regiment made their way through the town and on the further side seized a train of 230 waggons of provisions and military necessaries, intended for Besançon and left standing in the railway-station.
While the Doubs was thus crossed by the IInd Corps at this point, so the VIIth Corps opened itself a passage across the Ognon at Marmay and Pin.