At two o'clock in the afternoon, Thielemann commenced his march upon Wavre; where the Corps arrived late in the evening, and took up its position at La Bavette, leaving the Ninth Infantry Brigade (General Borcke) and the Cavalry Brigade of Colonel Count Lottum, on the right bank of the Dyle. In this position the Corps was now rejoined by Colonel Marwitz' Cavalry Brigade, which had retired by Tilly; as also by the 2nd Battalion of the 3rd Kurmark Landwehr, and the two Squadrons of the 6th Kurmark Landwehr Cavalry, which troops had been left at Dinant. The Squadron of the 7th Uhlans that had been detached to Onoz, also joined, but having fallen in with a superior force of the Enemy's Cavalry, had experienced a great loss. The two Squadrons of the 9th Hussars, belonging to this Corps, had not yet arrived from Ciney.
The Prussian Head Quarters were established, early on the 17th, at Wavre. The veteran Field Marshal, who was still suffering considerably in consequence of his fall, was obliged to seek rest the moment he arrived there, and did not quit his bed during the remainder of the day.
In the course of the forenoon, Lieutenant Massow, who had been despatched with a message to the Duke of Wellington, returned with the one from his Grace, communicating the intention of the latter to fall back upon Waterloo and accept a battle there, provided he received the support of two Prussian Corps. (See page 264.) There was every disposition to enter into this proposal, but some degree of uncertainty existed as to whether Bülow's Corps would join the Army on the 17th, as also a certain misgiving respecting the Park of Ammunition of both Zieten's and Pirch's Corps, which had been directed upon Gembloux, a circumstance that excited apprehensions as to the possibility of furnishing the much needed supply of ammunition to these Corps which were at hand. In this state of uncertainty, no other resolution could be adopted than that of holding the position in front and in rear of the Dyle (with the Advanced Guard of the Fourth Corps as far forward as Mont St Guibert), until the required ammunition should be obtained; and Blücher deferred replying to Wellington's communication, in the hope that his Army would very soon be relieved from the unpleasant circumstances above mentioned.
While the Prussians were thus effecting their retreat in good order, along the cross roads of that part of the country (high road there was none), no corresponding activity manifested itself on the part of the French, whom the morning's dawn found still lying in their bivouac. Their Vedettes stood within half a mile of the Columns of Thielemann's Rear Guard; the retreat of which, not having commenced until after sunrise, might have been easily remarked: and had the French detached but the smallest Patrol, they could not have failed to discover the direction of that retreat—whether towards Namur or Gembloux.
It was not until after Thielemann had retired a sufficient distance to escape further notice that any disposition for movement occurred to disturb the perfect quietude of their repose. Then, Pajol with a Division of his Light Cavalry Corps, under Lieutenant General Baron Soult, consisting of the 1st, 4th, and 5th Hussars, was detached in pursuit of the Prussians. He struck into the Namur road, and shortly afterwards Lieutenant General Baron Teste's Infantry Division of Lobau's Corps (the Sixth), followed in support, and took up a position on the Heights of Mazy.
Pajol had not proceeded very far when he perceived a Prussian Battery retiring upon Namur, which he lost no time in capturing and forwarding to Head Quarters; where the circumstance strengthened the belief that Blücher had retreated by that road. It was the Prussian Horse Battery No. 14, belonging to the Second Corps, which, having towards the end of the Battle expended every shot, had driven off the Field to procure a fresh supply of ammunition, but had not succeeded in falling in with the Reserve Ammunition Waggons. The Battery neither returned to its own Corps, nor did it comply with Thielemann's express Order to march upon Gembloux, but consumed much time in uselessly driving first in one direction, and then in another. It was accompanied at this moment by a Squadron of the 7th Prussian Uhlans, which the Third Corps had neglected to recall from Onoz. The Squadron retired on the approach of the French Cavalry, and escaped with a loss of 30 men; but all the guns fell into the hands of the Enemy.
Pajol, feeling at last some reason to doubt that Namur was a point in the Prussian retreat, diverged from the high road, and proceeded to St Denis, where he was joined by Teste's Division. A Brigade of Excelmans' Cavalry Corps had been detached to offer support to Pajol, should the latter require it; but in consequence of certain information, gained upon the road, it was subsequently directed to proceed towards Gembloux, on approaching which it discovered traces of the Prussian retreat.