The Duke of Wellington had only offered battle with the assurance that Prince Blucher would send at least one corps to join the battle. Knowing that the Prussians had been at Wavre the previous night and assuming that they would march with first light, around 4 a.m. the Duke had confidently calculated on receiving Prussian aid before the battle actually commenced, or at least no later than 11 a.m. He therefore spent the morning expectantly awaiting news of their arrival, but he was to remain disappointed. Nervous for news, patrols were frequently sent out beyond his left wing seeking reassuring information. This first came around 10 a.m. from a Major Thomas Taylor of the 10th Hussars, who reported having met a few Prussian officers at Chapelle St. Lambert, they had confirmed that a Prussian corps of twenty five thousand men under General Bulow was approaching and were presently about five miles away from them. With the news that the Prussians were coming soon, Wellington could concentrate fully on the battle in his front.
But the arrival of the Prussians was to be delayed greatly beyond Wellington’s expectations because of the poor condition of the roads. Bulow’s corps, being the freshest and largest, had been ordered to march at dawn from their overnight encampment at Dion le Mont, three miles south east of Wavre. This corps was the furthest away from Wellington’s position which complicated issues, as it had to march past the encampments of the other corps and delayed their own march for many hours. The 15th Brigade led the march; they set off as ordered at 4 a.m., however due to subsequent delays the rear of the corps was only just setting off from the camp six hours later. And to make the situation worse, as the rearguard troops began to march off, the baggage train was attacked by Exelman’s cavalry which caused the 1st Silesian Landwehr and 2nd Pomeranian cavalry Regiments to retrace their steps to drive the French away. They successfully drove the French cavalry off but these regiments subsequently failed to arrive in time to fight at Waterloo.
Because of the proximity of Grouchy, it was deemed too dangerous to march westward on the south side of the River Dyle, therefore the entire corps was ordered to pass the narrow bridge and road through Wavre which was a major bottleneck. The situation was not helped when a fire broke out in the town, but it only transmitted to a couple of houses and the troops and artillery of Bulow’s Corps were soon able to continue their march.
Having passed Wavre, the troops continued on the road for Chapelle St. Lambert and the leading elements of Bulow’s corps began arriving there soon after 10 a.m. The II Corps of General Pirch was to follow Bulow, but was also forced to halt by the fire at Wavre and it was gone 4 p.m. before the whole of his corps had passed Wavre.
Ziethen’s I Corps were not ordered to march from their encampment above Bierges until after 11 a.m. when it was definite that Wellington was fighting at Waterloo and it began its march almost immediately, although it left a detachment behind to protect the wing of Thielmann’s corps in Wavre.
The 15th Brigade, leading Bulow’s Corps, stood at Chapelle St. Lambert from 10 a.m. patiently awaiting the arrival of the other brigades before approaching any nearer to the battlefield; but it was fully 2 p.m. before the 16th Brigade finally arrived and another hour before the 14th Brigade who formed the rearguard, could come up. Bulow was initially cautious because there were no sounds of battle in his front, had Wellington retreated leaving him to march on the French alone?
But all doubts were allayed at 11.30 a.m. as a tremendous cannonade announced the beginning of a great battle. At midday, after a conference with Muffling, Bulow agreed to move forward via the village of Lasne and having formed up between La Haye and Aywieres, to attack the village of Plancenoit, which lay in the right rear of the French army. But before moving, Bulow ordered forward a major scouting party to establish where exactly the French were.
At around 2 p.m. Napoleon received a long message from Grouchy with numerous intelligence reports attached. It clearly identified that three corps of the Prussian army had marched with the avowed intention of joining with Wellington’s army, but indicating that their line of march was towards Brussels, not towards Mont St Jean. This clearly indicated to Napoleon that the Prussians were not a threat that day. Lieutenant Colonel La Fresnaye, who carried this message, does not record any particular reaction by Napoleon and he remained with the Emperor for the remainder of the day.
Knowing that the other brigades were now closing up with him, Bulow, acting on the favourable reports from his scouts, decided to march the 15th Brigade to Paris wood at 2 p.m.; they found the Lasne valley boggy from the heavy rains but unguarded.
The thick Belgian mud sapped the strength of the artillery horses as the cannon sank deep in the loam and simply refused to move whilst the infantry found their boots being sucked from their feet; but with the urging of Marshal Blucher and immense determination, they finally crossed the Lasne, arriving at Paris wood at a little after 3 p.m. when pickets were placed at every exit to maintain the secrecy of their arrival. By 4 p.m. the 16th Brigade and the cavalry of the corps had also joined and another half an hour later brought the 13th Brigade up as well, having rested at Chapelle St. Lambert for some three hours. The reserve artillery and 14th Brigade arrived at Paris wood by 5 p.m. with the 5th Brigade of II Corps marching close behind.
By 16:30 however, Blucher was becoming increasingly worried about Wellington’s ability to continue to stand against the French assaults and he saw signs of troop movements that seemed to signify a withdrawal.
He ordered Bulow to launch an immediate attack with his two brigades and his cavalry without waiting for support. Bulow remonstrated, but Blucher insisted that they must do something to relieve the pressure on Wellington’s army. As Bulow’s troops went forward, pushing the French cavalry videttes back, the 13th Brigade and his corps artillery finally arrived to strengthen the attack.
Lobau was surprised by this assault on his right, but soon placed his brigades of troops and supporting artillery along a ridge of high ground to the north of Plancenoit village to face this new threat. His small corps only numbered just over 7,000 infantry and about 3,000 cavalry with which to defend against Bulow’s 30,000 men. As Bulow advanced, he immediately sent part of the 15th Brigade out on his right to secure Frichermont and its neighbouring wood, to prevent any flank attack from Durutte’s troops. This was achieved with relative ease and the Prussians linked up with Saxe Weimar’s Nassau troops, but not without a number of ‘friendly fire’ incidents.
The rest of the 15th Brigade then moved on to engage Lobau’s main force on the ridge north of Plancenoit, whilst the 13th Brigade followed them in reserve. The 16th Brigade marched forward with their artillery and the cavalry protecting their flanks, determined to take the village of Plancenoit. Possession of the village would leave Napoleon’s rear completely unprotected, making his army very vulnerable; it had to be taken at all costs. The French cavalry videttes retired slowly in the face of Bulow’s advance and were eventually replaced by a cloud of infantry skirmishers who disputed every foot, but continued to retreat slowly until the Prussians finally reached the outskirts of the village.
This Prussian movement was also accidentally discovered by General Bernard, an aide to Napoleon, who soon reported his discovery. Eventually, around 4:30 p.m. a patrol arrived with a captured Prussian Hussar who readily revealed that the troops they could now see attacking Plancenoit were indeed Bulow’s Corps , not Grouchy. Seeing that Lobau’s Corps on the ridge was under severe pressure and mindful that the loss of the village would spell disaster for his army, Napoleon ordered the entire Young Guard Division, commanded by Comte Duhesme to occupy it and hold it. He rushed his troops into ‘Attack columns’ and sent all eight battalions into the village. The village of Plancenoit would be fought for, to the death; here the Young Guard were determined to make a stand.