Meanwhile, Grouchy began his retreat. His troops had reached the line La Bavette-Rosieren, in their pursuit of Thielemann, and now Excelmans’ Cavalry was sent off with orders to make all speed to Namur and secure the bridges over the Sambre at that place. Excelmans reached Namur at 4.30 P.M., a little more than five hours to cover 30 miles by devious lanes and byways in a terrible condition after the rains.
Gérard’s Corps, preceded by the Seventh Cavalry Division (six squadrons under Vallin, who had taken Maurin’s place), re-crossed the Dyle by the bridge at Limale, and moved by a narrow lane to the main Namur-Brussels road. Vandamme’s Corps withdrew from La Bavette, and marched through Wavre, Dion-le-Mont, Chaumont, Tourinnes, Sart à Walhain, Grand Leez, St Denis to Temploux on the Namur-Nivelles road, where it arrived at 11 P.M. and there bivouacked. Gérard’s Corps had reached Temploux an hour earlier.
Pajol, in command of the rear-guard, which was composed of the Fourth Cavalry Division—twelve squadrons, under Baron Soult—and Teste’s Infantry Division, demonstrated against Thielemann to keep him occupied until Wavre had been cleared, and then retreated by Corbaix, Walhain, Sauvenière, to Gembloux, where he bivouacked for the night.
As has been seen, Pirch was at Mellery with the Second Corps during the 19th from 11 A.M.; but he did not wish to risk attacking Grouchy without news of Thielemann. Grouchy’s army was still in good order and capable of stout fighting, but Pirch might have assisted the general situation by at least threatening Gérard’s right flank as he retreated. It is not likely that Grouchy would have checked his retreat on Namur, even if Pirch had shown himself, but Gérard would have been obliged to face round, and might possibly have been cut off; or if Grouchy had halted to confront Pirch, Thielemann would have had a good opportunity to attack him in flank.
Thielemann only heard of the French retreat towards 6 P.M. on the 19th, and his intelligence came through General Borcke, who discovered Grouchy’s movement, from St Lambert. Pajol had a rear-guard still in front of Thielemann, and as the latter’s troops were tired with their recent exertions, the Prussians postponed their pursuit until the next day, the 20th, when Borcke was ordered to march at daybreak with the Ninth Division from St Lambert, across the Dyle, and towards Namur.
At daybreak on the 20th, Grouchy’s rear-guard left Gembloux and marched on Namur by St Denis and La Falize. His infantry left Temploux about 9 A.M. Gérard’s Corps was intended to lead, Vandamme’s Corps covering the retreat of the Fourth, but Vandamme upset the arrangements by betaking himself over-night to Namur, leaving no instructions behind him for his Divisional generals. Consequently, the Divisions of the Third Corps moved off by themselves, early in the morning, and Gérard’s Corps, which was carrying the wounded with it, was left uncovered. A short distance beyond Temploux, the column was attacked by Prussian cavalry which had been sent off in pursuit by Thielemann at daybreak that morning. And at the same time, more cavalry were seen coming against the rear, along the Nivelles-Namur road. This was the cavalry heading Pirch’s Corps, which had marched from Mellery to Sombreffe. Gérard’s column had now stumbled on Vandamme’s rear-guard, posted 3 miles outside Namur; and Vandamme himself coming out from Namur, Grouchy ordered him to clear the road for the Fourth Corps, and cover its march with his rear-guard.
Thielemann’s Cavalry, accompanied by a battery of horse artillery, had come on at a great pace, and were almost too exhausted to attack the French with any vigour; but they managed to drive back the enemy’s cavalry and capture three guns. Further attack on the French rear-guard was left to Pirch’s Corps, which was now hurrying up.
The French retreated through Namur, after being well treated by the inhabitants (who supplied them with food, transport, and boats), and leaving Teste’s Division with eight guns in defence of the town against Pirch’s Corps. The remainder of Grouchy’s army crossed the Sambre by the Namur bridge and marched on Dinant by the valley of the Meuse.
In Namur, Teste made a brilliant defence. The town was fortified, but the works were out-of-date and dilapidated; and there was no time to improve the local resources. Teste’s men only numbered 2,000, with eight guns, and Pirch’s Corps was some 20,000 strong. All the wounded, the baggage, and the transport had been sent across the Sambre, and the bridge barricaded.
Pirch had suffered severely in his attack on Vandamme’s rear-guard outside Namur, losing over 1,200 men. The French had beaten back his three assaulting columns, and withdrawn into the town without letting the Prussian cavalry cut them off. Consequently Pirch was in no mind for a costly assault on Namur while Teste’s Division held the place; and he knew that Teste would not hold his position longer than was absolutely necessary for Grouchy with the main body to gain a safe distance. He contented himself with holding the enemy’s attention in front, while he despatched the main body of the Seventh Division to threaten the retreat over the Sambre. But as soon as the main portion of Grouchy’s army had cleared the river, Teste began to make his own preparations for retreat. He ordered a sortie to be made against the Prussians on the north, to gain time and to divert their attention from the bridge; and when all was ready, he withdrew his troops rapidly in single file across the parapets of the barricaded bridge, setting fire to a heap of faggots and lumber piled up against the enemy’s end. The guns had to be left behind.