The Detachments left by the Third Brigade at Farciennes and Tamines, had been previously called in, and effected their retreat without any molestation, as did also, subsequently, the Second Brigade from Lambusart, by Boulet, towards Fleurus, protected by the Reserve Cavalry.
Zieten's Corps, at three o'clock in the morning had possessed a line of Advanced Posts, from Dinant on the Meuse, crossing the Sambre at Thuin, and extending as far as Bonne Esperance, in advance of Binche; thus stretching along a space of from forty to fifty miles in length: its main force occupied the Sambre from Thuin as far as its confluence with the Meuse, an extent of, at least, thirty six miles, exclusive of the numerous windings throughout the whole course of the river between those two points. The men had, since daybreak, been constantly under arms, in motion, and almost as constantly engaged, pursued, and assailed upon all points by an overwhelming superiority of force, headed by the élite of the French Cavalry; and it was not until about eleven o'clock at night that the Corps effected its concentration in position between Ligny and St Amand, at a distance varying from fourteen to twenty miles in rear of its original extended line of Outposts; after having successfully and gloriously fulfilled the arduous task imposed upon it of gaining sufficient time for the concentration, on the following day, of all the Prussian Corps, by stemming, as well as its scattered force would admit, the imposing advance of the whole French Army.
The loss of the First Prussian Corps d'Armée on the 15th of June, amounted to 1200 men. The Fusilier Battalions of the 28th Regiment and of the 2nd Westphalian Landwehr, reduced to mere skeletons, were united, and formed into one Battalion.
Before ten o'clock on the morning of the 15th, a further Order was despatched from the Prussian Head Quarters to the Third Corps d'Armée, to the effect that after resting during the night at Namur, it was to continue its march upon the morning of the 16th, towards Sombref.
At half past eleven o'clock in the forenoon a despatch was forwarded to Bülow, announcing the advance of the French, and requesting that the Corps after having rested at Hannut, should commence its march upon Gembloux by daybreak of the 16th, at the latest.
By three o'clock in the afternoon of the 15th, the Second Corps d'Armée had taken up the position assigned to it between Onoz and Mazy in the immediate vicinity of Sombref, with the exception, however, of the Seventh Brigade, which, having been stationed in the most remote of the Quarters occupied by the Corps, did not reach Namur until midnight. Here the latter found an Order for its continuance in Namur until the arrival of the Third Corps d'Armée; but as this had already taken place, the Brigade, after a few hours' rest, resumed its march, and joined its Corps at Sombref about ten o'clock in the morning of the 16th June.
Thielemann passed the night at Namur, which he occupied with the Tenth Brigade; the Ninth Brigade bivouacked on the right, and the Eleventh on the left, of Belgrade, a village at a short distance from the town, on the road to Sombref; the Twelfth Brigade in rear of the Ninth; the Reserve Cavalry at Flavinne, between that road and the Sambre; and the Reserve Artillery on the left of the road.
It has already been explained that on the 14th, Blücher sent off a despatch to Bülow desiring him to make such a disposition of his Corps as should enable his troops to reach Hannut in one march; and that at midnight of the 14th, a second despatch was forwarded, requiring him to concentrate the Fourth Corps at Hannut. The first of these despatches reached Bülow, at Liege, at five o'clock on the morning of the 15th; when he issued the necessary Orders with an instruction that they should be acted upon as soon as the troops had dined, and forwarded a report of this arrangement to Head Quarters. These Orders to his troops had been despatched some hours, and the consequent movements were for the most part in operation, when, towards noon, the second despatch arrived. Bülow, considering the effect which the change required by this new Order would have upon the troops, inasmuch as their reception was prepared in quarters to which, in this case, they would no longer proceed, and they would have nothing provided for them in the destined bivouac near Hannut, also as a great proportion of them could not receive the Orders for the change in the direction of their march until evening, decided upon deferring the new movement until daybreak of the 16th. The despatch, moreover, did not require him to establish his Head Quarters at Hannut, but merely suggested that the latter appeared the most suitable for the purpose. The General was, besides, perfectly unconscious of the commencement of hostilities, which, indeed, he had expected would be preceded by a Declaration of War; and he had also good grounds for an opinion which he had formed that it was in contemplation to assemble the whole Army at Hannut.
He made a report to Head Quarters of his reasons for deferring the execution of the Order, with the intimation that he would be at Hannut by midday of the 16th. Captain Below, on Bülow's Staff, who carried this despatch, arrived at nine o'clock in the evening of the 15th at Namur, where he discovered that the Head Quarters of the Army had been transferred to Sombref.