In the meantime reinforcements, consisting of the advanced guard of Reille’s Corps, were being pushed along the Gosselies road, with a view to cutting off Steinmetz’s retreat, and separating Zieten’s Corps from Wellington’s army. This move of the French was very skilful, but Steinmetz, perceiving that his position was one of great danger, made a feint against the French left flank, and, covering his retreat with a regiment of Lancers and one of Hussars, withdrew to Heppignies, a village half-way between Gosselies and Fleurus. Had Steinmetz been caught and surrounded at Gosselies, Blucher would have been weaker by one Division in the great struggle at Ligny next day; and he could ill afford to reduce his numbers.
Ney, who had taken over the command of the French Left Wing, and who was at this time pushing on with Piré’s Cavalry and Bachelu’s Infantry to Frasnes, sent Girard’s Division of Reille’s Corps to pursue Steinmetz. Girard occupied Ransart, and made an attack upon Heppignies, but the Prussians drove him back, and retired in good order to Fleurus, thus rejoining the main body of their Corps, and effecting their retreat in a very skilful manner.
In the Prussian centre, meanwhile, Pirch II.‘s Second Division, which had been ordered to gain time for the retreat of the First, retired to Gilly, on the road to Fleurus, when the French entered Charleroi. At Gilly the Prussians took up a strong position and prepared to delay the French advance as much as possible. Pirch’s line of defence stretched from Soleilmont on his right, to Châtelineau on his left; and a small stream ran in his front at the foot of the ridge on which his position stood. His left flank was further strengthened by a detachment holding the bridge over the Sambre at Châtelet. Cavalry patrols watched the valley of the Sambre for the approach of Gérard’s Corps, which was already marching on Châtelet. Had Gerard marched earlier from Phillippeville, he would have prevented, by his occupation of Châtelet earlier in the day, Pirch’s stand at Gilly.
Grouchy had orders to take Vandamme’s Corps and Excelmans’ Cavalry, and pursue the Prussians along the Charleroi-Fleurus road; but he was deceived as to the strength of the enemy at Gilly. Fearing to attack without further reinforcements, he rode back to Napoleon for instructions. This was at about 5 P.M. Napoleon, fretting at the delay, which he regarded as needless, himself rode out with four squadrons of Cavalry of the Guard, and reconnoitred Pirch’s position. He soon satisfied himself as to Pirch’s real strength, and gave Grouchy orders to attack at once. Accordingly, at 6 P.M., artillery fire opened on the Prussians from two batteries; three infantry columns from Vandamme’s Corps were ordered to assault in front, and two cavalry brigades to menace the Prussian flanks. Pirch was preparing to reply to the French artillery fire, when he received orders from Zieten to retire on Fleurus _viâ_ Lambusart. As soon as he began to withdraw his battalions, the French cavalry, under Letort, made a vigorous attack. The Prussian infantry resisted stoutly, and a regiment of dragoons, with great boldness, charged the French squadrons with such effect that they were for the moment checked, and the Prussians were able to gain the cover of the wood of Fleurus. A battalion of the Sixth Regiment of the Line, by forming square repeatedly, bravely kept the enemy’s cavalry at a distance, and gained very valuable time for the retreat of the rest of Pirch’s Division. In front of Lambusart, where Pirch joined some battalions of the Third Division and Roder’s Reserve Cavalry, a fresh position was taken up, and a regiment of Brandenburg Dragoons, sent by Zieten to support Pirch II., did excellent service by charging the French horsemen and checking their pursuit. Towards eight o’clock three batteries of French Horse Artillery, which accompanied the cavalry, opened fire on Lambusart; but night was coming on, and the attack died out very shortly afterwards. Pirch II. then withdrew to Fleurus, where he joined the remainder of Zieten’s Divisions, and the whole Corps retreated to Ligny. Steinmetz had reached Fleurus from Heppignies at about 10 P.M.