It was half past four o'clock when the Fifteenth and Sixteenth Brigades debouched from the Wood of Paris; the former on the right, the latter on the left; and each in the usual Brigade formation for advance peculiar to Prussian tactics. The direction of the attack was perpendicular to the Right Flank of the French Army; and consequently, also, to the Charleroi road, which constituted the French main line of operation.
In order to cover the Left Flank, Colonel Hiller, commanding the Sixteenth Brigade, detached both the 3rd Battalions of the 15th Regiment and the 1st Silesian Landwehr, under Major Keller, to keep a look out in that direction as far as the rivulet of the Lasne; beyond which, Major Falkenhausen was scouring the country with one hundred Horsemen of the 3rd Regiment of Silesian Landwehr Cavalry.
General Losthin, commanding the Fifteenth Brigade, detached three Battalions towards Frischermont and Smohain, to cover the Right Flank. They were the 2nd Battalion of the 18th Regiment, and the 3rd Battalion of the 3rd Silesian Landwehr, followed by the 1st Battalion of the former Regiment.
Domon's Cavalry continued drawn up en potence, and was at a considerable distance from the Prussian Advance, when Blücher ordered a cannonade to open upon it; more with a view to make known his arrival to the Anglo-Allied Army, and to induce the French to withhold the employment of a still greater force against the latter, than from any motive affecting his own immediate operations at the moment.
Domon now sent forward a Regiment of Chasseurs à Cheval to attack the Prussian Column, whilst he followed with his whole Line. Hereupon the 2nd Silesian Hussars and the 2nd Neumark Landwehr Cavalry moved through the intervals of the Infantry, and formed up in front; the Hussars to the left, and the Landwehr to the right. They then advanced, followed by the 3rd Silesian Landwehr Cavalry in support, and drove back the French Chasseurs; but becoming menaced in flank, and observing Domon's whole Line advancing, they were, in their turn, compelled to retire. This movement was covered by the Horse Battery No. 11; and more particularly by Captain Schmidt's Foot Battery of the Fifteenth Brigade, which drew up to oppose the pursuit of the French Cavalry. The vigorous fire which continued to be maintained by both these Batteries, combined with the advance of the Prussian Infantry Columns, induced Domon to decline following up his attack at the moment.
The three Battalions already mentioned as having been detached to the right, had, by this time, reached Smohain. Their advance in that direction had been conducted with so much caution, that they debouched from the south-eastern inclosures of the Village most unexpectedly for both the Allied troops in that vicinity, and the Infantry forming the extreme Right of the French Front Line. The Prussians continued to advance; crossed the principal fence which separated them from the French extreme Right, and drew up in Line almost at right angles with the direction of the Enemy's front—two Battalions in Line, with the third in support. It was half past five o'clock when this took place.
The French at once advanced against them; whereupon the Prussians retired, and after regaining the hedges in the valley, lined the latter as Skirmishers, and maintained a vigorous and successful tiraillade with their opponents.
In the mean time Napoleon, judging from the boldness of the Prussian Advance, that considerable support was at hand; and apprehensive, no doubt, of the evil consequence likely to arise from that Advance, if not promptly and effectually checked, had ordered the Sixth Corps, under Count Lobau, to move forthwith to the right from its reserve station in rear of La Belle Alliance; and, in conjunction with Domon's Cavalry, to take up a position favourable for repelling the attack by which he was menaced on that side of the Field.
Blücher, observing this disposition, the execution of which was effected with great rapidity and in good order, proceeded to give a broader and more imposing front to his own troops. He extended his Right Flank to the wooded Heights of Frischermont, and rested his Left upon a ravine descending to the Lasne, close to the Wood of Virère. The Reserve Cavalry, under Prince William of Prussia, was put in motion, in two Columns, towards the Left Flank; on which it was subsequently formed up.
When Lobau's Corps moved off to the right, the Regiments of the Old and Middle Guard advanced and took up the position, in reserve, which it had occupied on the Heights in rear of La Belle Alliance.