If the Prussians attempted to outflank the Churchyard by advancing along the low open space on its right; they became exposed to the commanding fire from its walls, to that from the opposite houses, and in front, to the Reserves. If they ventured to pass close by its left they had but a narrow road open to them, bounded by the Churchyard wall on one side strongly lined by the defenders, and by houses on the other which the Enemy still occupied, and presenting also at its further extremity a Farm House and its offices in flames, situated so close to the Churchyard as to conceal by its smoke any Column of Reserve that might be posted in that quarter.
Hence it was determined to act upon a broader extent of Front, and to turn the entire Village on both Flanks; so as either to force, or to intercept, the retreat of the Enemy from his stronghold in the Churchyard. On the Prussian Left, Major Witzleben, with the Fusilier Battalion of the 25th Regiment, had already crossed the rivulet which divides the Village into two nearly equal parts, and was attacking that portion of the French Guard which was posted upon the narrow ridge which lies between that rivulet and the Lasne. His Skirmishers were joined upon their left by those that had preceded the 1st and 2nd Battalions of this Regiment; and which latter having pushed through the Wood of Virère, were now following close up in support of the attack on this part of Planchenoit. These Skirmishers were also connected on their left with those of the Fusilier Battalions of both the 15th Regiment and the 1st Silesian Landwehr, under Major Keller, who was advancing along the right bank of the Lasne. Along the crest of this ridge runs a narrow road, with several cottages on either side of the latter: the ground is throughout intersected with hedges and studded with trees; and altogether admirably adapted for a protracted defence by Light Troops. Every house, every lane, and every hedge was gallantly contested.
The Prussians not only boldly attacking in front; but skilfully and gradually turning the ridge upon both sides, at length gained possession of all this portion of the Village, and thus outflanked the troops in the Churchyard, who maintained to the last a most desperate defence. In the mean time, the houses and inclosures on the left of the Church had also been turned on that side by the Right of the Prussian attack: and principally by the 5th Westphalian Landwehr, the Skirmishers of which had beaten back their opponents close under the walls of the burning buildings; the bright flames from which, gleaming upon the combatants, who rent the air with their shouts, gave a peculiar wildness to this scene of mortal strife. But still more wild and awful must have been the scene within the Church, as the red flood of light which they poured through the windows of the aisles, fell upon the agonised and distorted features of the wounded and the dying with which that sacred edifice was at this moment filled.
The Prussians continued pressing forward along both Flanks of the Village, driving the Imperial Guard from house to house, from hedge to hedge, and from tree to tree, until at length it became obvious to the French that their rear would soon be intercepted. The latter were also by this time fully aware of the déroute of the main Army; and, giving up all for lost as they fell back upon the western portion of the Village, they made a hasty and disorderly retreat towards Maison du Roi.
The Chasseurs of the Old Guard were the last to quit the Churchyard, and suffered severely as they retired. Their numbers were awfully diminished; and Pelet, collecting together about 250 of them, found himself vigorously assailed by the Prussian Cavalry from the moment he quitted the confines of Planchenoit and entered upon the plain between the latter and the high road. At one time, his ranks having opened out too much in the hurry of their retreat, some of the Prussian troops in pursuit, both Cavalry and Infantry, endeavoured to capture the Eagle, which, covered with black crape, was carried in the midst of this devoted little band of Veterans. Pelet, taking advantage of a spot of ground which afforded them some degree of cover against the fire of grape by which they were constantly assailed, halted the Standard Bearer, and called out "A moi, Chasseurs! sauvons l'Aigle ou mourons autour d'elle!" The Chasseurs immediately pressed around him, forming what is usually termed the Rallying Square; and, lowering their bayonets, succeeded in repulsing the charge of Cavalry. Some guns were then brought to bear upon them, and subsequently a brisk fire of musketry: but notwithstanding the awful sacrifice which was thus offered up in defence of their precious charge, they succeeded in reaching the main line of retreat, favoured by the universal confusion, as also by the general obscurity which now prevailed; and thus saved alike the Eagle and the honour of the Regiment.
The Reserve Cavalry of the Second and Fourth Prussian Corps received Orders to pass to the front through the Infantry: that of the Fourth Corps, under Prince William of Prussia, moved by the right of Planchenoit, as also through the Village itself; but its progress was greatly impeded by the fugitives that crowded towards Maison du Roi.
In the mean time, the Prussian Battalions that had been detached for the protection of the Left of the attack upon Planchenoit, namely the Fusilier Battalion of the 15th Regiment, and that of the 1st Silesian Landwehr, under Major Keller, as also that of the 25th Regiment, under Major Witzleben, had turned the Village, and followed the Enemy nearly in the direction of Maison du Roi. They met with some resistance on the part of the Battalion of the Grenadiers of the Imperial Guard, which had advanced from Caillon, in pursuance of the Orders it had received, into the Wood of Chantelet; but they soon forced their way to the high road, and by their presence added greatly to the disorder in which the Enemy was flying from the Field.
Major Falkenhausen, having remarked the retreat of the French, as he stood on the Height of Seroulx, to which he had been detached with one hundred Horsemen of the 3rd Silesian Landwehr Cavalry, also moved down upon the high road, and charging the Flank of the flying Foe, tended still further to augment the alarm and confusion that prevailed.
When the French Imperial Guard was falling back from Planchenoit in disorder and confusion towards the high road between Rossomme and Maison du Roi, Wellington's Advanced Brigades had reached the former place. It was about half past eight o'clock—perhaps somewhat later—and the darkness, which had been rapidly setting in, had become so great as to render it difficult to distinguish one particular body of troops from another.
Some little time before this, one of the Prussian Advanced Regiments of Cavalry, suddenly entering the high road between La Belle Alliance and Rossomme, came into partial collision with the 18th British Hussars; who, not anticipating the presence of any other foreign troops in that vicinity than those of the French Army, commenced an attack upon them: cuts were exchanged, and some few lives lost, before the error was corrected.