He ordered the Batteries of the First Corps d'Armée (Zieten's) to be suitably posted for impeding the Enemy's advance. The three Heavy Batteries of the Corps were immediately drawn up on the Height between Ligny and St Amand. They were supported by the Battery of the First Brigade, posted in rear of St Amand. Somewhat later, when the direction of attack by Gérard's Corps became more developed, the Battery of the Third Brigade was placed on the right of Ligny, near a quarry, and the Battery of the Fourth Brigade on the left of the Village, upon the declivity descending to the rivulet. The Battery of the Second Brigade, the Foot Battery No. 1, and the Horse Battery No. 10, remained in reserve. Of the remaining Horse Batteries of the Corps, one continued with the Cavalry under General Röder (which was posted in a hollow, as before stated, between Ligny and Sombref), and the other was with the 1st Silesian Hussars, which Regiment had been detached in observation on the Right Flank of the Army, and posted between the northern extremity of the village of Wagnelé and a large pond contiguous to the old Roman road.
By the time the action commenced in front of St Amand and Ligny—half past two o'clock—Blücher was satisfied that no necessity existed for any movement of his Third Corps d'Armée to the right; and he therefore ordered it to proceed from the position it had hitherto held in Columns upon the two high roads near Sombref, and form the Left Wing of his line of battle; resting its Right upon Sombref, and occupying the Heights, at the foot and on the declivities of which are situated the Villages of Mont Potriaux, Tongrines, Tongrenelle, Boignée, Balatre, Vilrets, and Botey.
The Ninth Brigade (General Borke) was formed in Brigade order in rear of Sombref and northward of the Namur high road, having detached one of its Battalions (the 3rd of the 8th Regiment) with the Foot Battery No. 18, to Mont Potriaux, where the former posted itself on the north, and the latter took up a favourable position on the south, side of the Church. The Eleventh Brigade (Colonel Luck) with the twelve pounder Battery No. 7, stood across the Fleurus high road, in front of the junction of the latter with the Namur road upon the Height of Le Point du Jour, having detached the 3rd Battalion of the 4th Kurmark Landwehr into the valley, where it occupied the houses in its immediate vicinity. Four Battalions of the Tenth Brigade (Colonel Kämpfen) were drawn up on the Height of Tongrines, resting their Right on this Village, and having in their front the Foot Battery No. 35, and at a short distance from their Left, the Horse Battery No. 18. The remaining two Battalions of the Brigade were detached, the 3rd Battalion of the 27th Regiment, to occupy Tongrines and the Castle of Tongrenelle, and the 3rd Battalion of the 2nd Kurmark Landwehr, to hold the Villages of Boignée and Balatre. The 2nd Battalion of the 3rd Kurmark Landwehr, belonging to the Brigade, as also two Squadrons of the 6th Kurmark Landwehr Cavalry, and two Squadrons of the 9th Hussars, attached to this Corps, still continued in the line of Outposts in the vicinity of Dinant, to observe Givet; and rejoined on the morning of the 17th of June. The Twelfth Brigade (Colonel Stülpnagel) with the Horse Battery No. 20, was formed in Brigade order, in reserve, near the Windmill, on the Height of Le Point du Jour. The Reserve Cavalry of this Corps, with the Horse Battery No. 19, was posted on the extreme Left of the position between Botey and Vilrets, whence it detached the 3rd Squadron of the 7th Uhlans to Onoz, in observation.
This position and the order of battle which was thus developed, were well calculated to answer the object which Blücher had in view, namely, to hold his ground long enough to gain sufficient time for the arrival of at least a portion of Wellington's forces, expected to join the Prussian extreme Right by the Namur road; as also, perhaps, for the arrival and co-operation of Bülow's Corps, in rear of Thielemann, by the Gembloux road. In either of these cases, if not previously favoured by the circumstances of the general battle about to take place, such a marked accession to his strength would enable him to assume the offensive; whilst, in the first mentioned, Wellington would effectually prevent a junction between Napoleon's and Ney's forces.
The position had been long before selected, and the whole of the ground had even been surveyed, with a view to meet the contingency which had now actually occurred; but then it must be remembered, that in this design the co-operation of the Fourth Corps d'Armée was fully contemplated, whereas the latter had now become a doubtful question: and hence it was that Blücher was led to place more reliance upon a direct support from Wellington, than would otherwise have been the case.
To accept a battle, notwithstanding the absence of Bülow's Corps, was undoubtedly the wisest course. The Enemy's force in the field did not appear to exceed that of the Prussians; and therefore, considering the nature of the position, the contest would, in all probability, become protracted, perhaps until the arrival of Bülow; perhaps, also, until the close of day, without any distinct advantage being gained by either party. In the former case, the required preponderance might instantly give a decidedly favourable turn to the scale; in the latter, the junction of the Fourth Corps during the night would enable Blücher on the following morning to attack his opponent with every prospect of success, and either to relieve Wellington, if necessary, from any pressure in his front, or so to combine his further operations with those of the British Commander, should the latter have held his ground and concentrated his Army, as to lead to the complete overthrow of both Napoleon's and Ney's forces.
To have declined the contest, and retired so as to effect a junction with his Fourth Corps, he must still, if he wished to act in close concert with Wellington, have abandoned his direct communication with the Meuse and the Rhine, whence he drew all his supplies; a result which might as well be trusted to the chances of a battle.
These considerations were also, in all probability, strongly seconded by a desire on the part of the Prussian Commander, and one perfectly in keeping with his ardent character, to take every possible measure which was at all warranted by the actual posture of affairs, for vigorously opposing Napoleon's advance.