The Army of the East under General Bourbaki.
While the French forces were engaged in constant fighting, in the north on the Seine and the Somme, in the south on the Loire and the Saône, General Bourbaki's army had nowhere made itself prominent. Since the 8th of December, when the 6th Cavalry Division had reported its presence at Vierzon, all trace of it had been lost. It was of course of the greatest importance to the supreme Command that it should know the whereabouts of so large an army; only the IInd German Army could acquire this information, and on the 22nd it received instructions to obtain the required enlightenment by means of reconnaissances.
On this errand General von Rantzau (commanding 25th Cavalry Brigade) set out from Montargis by the right bank of the Loire towards Briare, where he found that the French had abandoned their position on the 25th; in the course of the next few days he met them, and was defeated.
The Hessian detachment was reinforced to a strength of three battalions, four squadrons and six guns, but was nevertheless driven back to Gien on the 1st of January. The French had displayed a force of several thousand Gardes-Mobiles, twelve guns, and a body of marine infantry. A noticeable fact was that some of the prisoners brought in belonged to the XVIIIth French Corps, which formed part of the Ist Army of the Loire.
A regiment of the 6th Cavalry Division sent out to reconnoitre into the Sologne, returned with the report that strong hostile columns were marching on Aubigny Ville. On the other hand, two waggon-drivers who had been taken prisoners declared that the French troops had been already moved from Bourges by rail, and the newspaper reports also pointed to the same conclusion; still, too much weight could not be attached to mere rumour as against circumstantial intelligence. It was therefore assumed at Versailles that the Ist Army of the Loire was still about Bourges, and that General Bourbaki, when again in a condition to fight, would act in concert with General Chanzy.
The two armies might attack the Germans at Orleans from opposite sides, or one might engage and detain them there, while the other marched to relieve the capital.
This, in fact, was what General Chanzy had in view. Since the 21st of December he had been resting in quarters in and about Le Mans, where railways from four directions facilitated the bringing up of new levies. His troops had no doubt great hardships to contend with there. In lack of shelter for such great masses part had to camp out under canvas in the snow, and suffered severely from the intense cold. The hospitals were crammed with wounded and small-pox patients. On the other hand, this close concentration was favourable to the reorganization of the details and the restoration of discipline; and the news from Paris urged the General to renewed action.
General Trochu had sent word that Paris unaided could not accomplish her freedom. Even if a sortie should prove successful, the necessary supplies for the maintenance of an army could not be carried with it, and therefore nothing but the simultaneous appearance of an army from without could meet the case. Now General Chanzy was quite ready to march on Paris, but it was indispensable that he should first know exactly what Generals Bourbaki and Faidherbe were doing.
It was clearly evident that concerted action on the part of three great Army Corps could only be devised and controlled by the chief power. The General therefore sent an officer of his Staff on the 23rd of December to Gambetta at Lyons, to express his conviction that only a combined and prompt advance could avert the fall of the capital. But the Minister believed that he knew better. The first news of a quite different disposition of Bourbaki's army only reached General Chanzy on the 29th, when it was already entered upon. Nor in other respects did Gambetta's reply convey either distinct orders or sufficient information. "You have decimated the Mecklenburgers," wrote Gambetta, "the Bavarians no longer exist, the rest of the German Army is a prey to disquietude and exhaustion. Let us persevere, and we shall drive these hordes from our soil with empty hands." The plan of the Provisional Government was to be the one "which would most demoralize the German army."[62]
Under instructions so obscure from the chief authority General Chanzy, relying on his own strength, determined to make his way to Paris without other assistance; but he soon found himself in serious difficulties.
On the German side there was no time to be lost in utilizing their position between the two hostile armies, advantageous as it was so long as those armies were not too near. The simultaneous attacks on the 31st December at Vendôme on the Loir, and at Briare on the Loire, seemed to indicate that the two were already acting on a concerted plan.
On New Year's day Prince Frederick Charles received telegraphic instructions to re-cross the Loir without delay, and strike at General Chanzy, as being the nearest and most imminently dangerous enemy. With this object the IInd Army was strengthened by the addition of the XIIIth Corps of the Grand Duke of Mecklenburg (17th and 22nd Divisions) and the 2nd and 4th Divisions of Cavalry. And in addition the 5th Cavalry Division was detailed to the duty of covering the right flank of the advance.
Only the 25th (Hessian) Division was to be left in Orleans as a possible check on General Bourbaki, and to maintain observation on Gien. But as a further provision, in case of need against a possible advance of the IInd Army of the Loire, General von Zastrow was ordered to the Armançon with the VIIth Corps;[63] and further the IInd Corps from the besieging lines was set in march to Montargis.
Prince Frederick Charles' arrangement was to have his three corps assembled on the line Vendôme—Morée by 6th January, and to order the XIIIth from Chartres on Brou.