By the evening of the 17th, the entire Prussian Army (with the exception of the Ninth and Thirteenth Brigades, and the Reserve Cavalry of the Third Corps, which arrived by six o'clock on the following morning) had assembled in the immediate vicinity of Wavre—two Corps on the right, and the remaining two Corps on the left, bank of the Dyle—in perfect order, and fully prepared to resume the offensive. Upon the two lines of retreat, the Rear Guards were well disposed at Vieux Sart and Mont St Guibert; where they continued during that night, and whence they retired leisurely on the following day. On the Prussian Left, Patrols were despatched towards the main road leading from Namur to Louvain. On the Right, a Detachment was sent from Zieten's Corps to Limale, on the left bank of the Dyle, to cover the Flank, and Patrols were pushed higher up the river, to communicate with the Post of Mont St Guibert. Major Falkenhausen had been detached, during the day, to Seroulx for the purpose of reconnoitring the country in the vicinity of Genappe, and of the high road to Brussels; and he succeeded in discovering, from the wooded tracts beyond Seroulx, the advance of the French Army along the chaussée. Patrols were also detached towards Lasne, Couture, and Aywiers, to observe the Defiles along the rivulet of the Lasne.
Such were the dispositions of the defeated Prussians on the evening of the 17th, while the victorious French had not advanced beyond Gembloux. The former had fallen back, in good order, upon a line with, and a short distance from, the Anglo-Allied Army on their Right; while their opponents, though encountering no obstacle of importance, had made but little progress, and were widely diverging from, instead of closely co-operating with, the main Army from which they had been detached. These dispositions, so ably planned and so efficiently performed, were well calculated to facilitate the grand operation of the morrow, namely, Blücher's flank movement to the right, to effect a junction with Wellington.
The retreat to Wavre did not in any way incapacitate the Prussian Army for the resumption of actively offensive operations. With respect to its material, it so happened that the Park of Reserve Ammunition Waggons had, in the first instance, been directed upon Gembloux; and Colonel Röhl, who superintended the Ordnance Department of the Army, sent his Aide de Camp during the night of the 16th to conduct this Reserve to Wavre; whilst he himself hastened to the latter town, for the purpose of putting the whole of the Artillery, accordingly as it arrived there, again in a fit state for action. The supply of ammunition, however, was necessarily incomplete; but in order to prevent any failure in this respect, should some mishap occur to the Park of Reserve Ammunition Waggons, a Courier was despatched to Maestricht, with directions for the speedy transport of a supply of ammunition from thence to the Army, by means of the common waggons of the country. Similar Orders were conveyed to Cologne, Wesel, and Münster: and, by way of precaution, an express was sent to Liege for the removal of the Battering Train to Maestricht; as also for the destruction, in case of danger, of the iron foundry in the Arsenal of the former place.
Fortunately, however, the Reserve Ammunition Waggons reached Wavre safely at five o'clock in the afternoon of the 17th. The Corps and Batteries were furnished with a complete supply of ammunition, and the Army was thus placed in a perfectly efficient state for commencing another battle. This turn of affairs was most encouraging, and Blücher delayed not another moment in despatching to Wellington the reply to which allusion has already been made. (See page 285.)
As regards the influence which the defeat at Ligny exercised over the morale of the Prussian Army, its injurious effects were made manifest amongst the newly raised drafts from the Rhenish and Westphalian Provinces, and from the Duchy of Berg. Of these troops, 8,000 men betook themselves to a flight which admitted of no check until they reached Liege and Aix la Chapelle. Among the Rhenish troops, particularly those from Provinces which had formerly belonged to France, there were many old French soldiers; and although several of them fought with great bravery, others evinced a bad disposition, and there were instances in which they passed over to their former companions in arms. Such, however, was not the case with the troops from the other western districts of the Prussian State: there was scarcely a single man amongst the missing, who belonged to any of the old Westphalian Provinces, Mark, Cleve, Minden, and Ravensberg, whilst several came from that of Münster.
But the morale of the great mass of the Prussian Army continued unshaken. The spirit of the troops was neither tamed nor broken; and their enthusiasm, though damped, had not been subdued. Unbounded confidence was placed in the firm decision and restless energy of their aged and venerated Chief; who, though suffering from the effects of his fall, by which his whole frame had sustained a severe shock, evinced not the slightest apprehension of fatal consequences to the Campaign resulting from this defeat. His unbending nature led him to cast aside for the moment those purely political interests and theoretically strategical principles, by which a more cautious and less enterprising Commander might have been induced to secure the line of the Meuse, and to preserve his direct communications with the Prussian States, and thus afford but a doubtful and an inefficient support to his Ally. Placing full reliance on the resources of his own mind, and on the stern, warlike character of his troops; he devoted his whole energies to the attainment of the one grand object—that of crushing Napoleon by combining with Wellington. This confidence in himself and in his soldiers was strikingly and characteristically manifested in the concluding words of a General Order which he issued to the Army on the morning of the 17th. "I shall immediately lead you against the Enemy;—we shall beat him, because it is our duty to do so."
Towards midnight of the 17th, a communication reached Blücher from General Müffling (already mentioned as having been attached to the British Head Quarters) to the following effect. "The Anglo-Allied Army is posted with its Right upon Braine l'Alleud, its Centre upon Mont St Jean, and its Left near La Haye; having the Enemy in its front. The Duke awaits the attack, but calculates upon Prussian support."
This intelligence was forwarded, at midnight, to General Count Bülow, accompanied by the following Order:—"You will therefore, at daybreak, march with the Fourth Corps from Dion le Mont, through Wavre, taking the direction of Chapelle St Lambert, in which vicinity you will keep your force concealed as much as possible, in case the Enemy should not, by that time, be seriously engaged with the Duke of Wellington; but should it be otherwise, you will make a most vigorous attack upon the Enemy's Right Flank. The Second Corps will follow you as a direct Support: the First and Third Corps will also be held in readiness to move in the same direction if necessary. You will leave a Detachment in observation at Mont St Guibert; which, if pressed, will gradually fall back upon Wavre. All the Baggage Train, and everything not actually required in the Field of Action, will be sent to Louvain."
Instructions, in conformity with the above, were also forwarded to the Commanders of the other Corps; and a communication of these arrangements was despatched to General Müffling, with an explanation that the fatigue of the troops could not possibly admit of earlier support. This General was, at the same time, requested to forward timely intelligence of the attack upon the Duke, and of the nature of that attack, that measures might be adopted accordingly.