Waterloo_ June 18, 1815_ The Battle for Modern Europe - Andrew Roberts [11]
Before daybreak, Wellington received a message that would make the gruelling night undergone by the British army wholly worthwhile. Blücher sent word that as soon as it was light enough to march, he would be sending not only Bülow’s corps (which had not taken part in Ligny) to Wellington’s aid, but two whole corps — virtually the entire Prussian army — leaving only one corps to guard Wavre against Grouchy coming up from Gembloux. This was about treble the numbers Wellington had been expecting and hoping for, and it completely altered his thinking about the battle that was clearly to be joined the next day.
Instead of merely a holding action in front of the large Forest of Soignes to his rear, through which there was only one road to Brussels, Wellington could now envisage doing to Napoleon what Napoleon had hoped to do to the Prussians at Ligny: crush the enemy with a surprise eruption of extra troops onto its flank in the course of the battle.
For Napoleon had not the first hint of a suspicion that the Prussians, largely through the superhuman efforts of their commander, had been transformed in less than forty-eight hours from a defeated force fleeing the battlefield of Ligny into a disciplined army ready to take the offensive against the French once again. Meanwhile Grouchy, despite the large force at his disposal, had failed to make significant contact with the Prussian rearguard. He had also taken seven hours to march the six miles to Gembloux, which even in the torrential rain was a tortoise-like speed.
Napoleon desperately needed that force to be commanded by a marshal of dash and verve, but instead he had given the job to Grouchy. The most impressive cavalry commander in Europe, Napoleon’s brother-in-law Joachim Murat, King of Naples, had fled Italy and offered his services, but the Emperor had turned him down. Marshal Davout was holding down the job of minister of war back in Paris, while Marshal Suchet was commanding the divisions guarding France’s eastern approaches. Most of the other twenty-six marshals were either dead, had declared for the Bourbons, or were refusing to commit themselves to either side.
The knowledge that his left flank would be protected by the Prussians encouraged Wellington to strengthen the right and centre of his line. He also left over 17,000 men (3,000 British and 14,000 Dutch and Hanoverian) off the battlefield altogether, stationing them nine miles to the west at a village named Hal, under the joint commands of Prince Frederick of the Netherlands and Lieutenant-General Sir Charles Colville, who were both under the overall command of General Lord Hill. These troops would, Wellington hoped, be able to prevent any extravagant outflanking movement on the right flank, since he suspected that Napoleon might only be feinting at the Charleroi—Brussels road and really intended to march on Brussels via Mons.
Many historians — and not only historians: Napoleon himself fastened upon it — have criticised Wellington for leaving so large a force a two-or three-hour march away from the battlefield and for not recalling them the moment it became clear that Napoleon intended no large-scale manoeuvre but only a ‘hard pounding’ attack up the centre. They have even likened Wellington’s detachment at Hal to Napoleon sending off Marshal Grouchy, thereby deliberately absenting a large body of men who could have been invaluable at the battle. In Wellington’s defence the historian Jac Weller has argued that:
On the morning of the eighteenth Wellington did not know the exact position of all French forces. He could see by personal observation that Napoleon had detached a considerable portion of his entire army. There were about 39,000 Frenchmen unaccounted for; he knew of Grouchy’s movements in general, but not his strength. If Grouchy had only half this force, the other half could have been moving to turn the Duke’s right flank. Wellington did not underrate Napoleon, he wanted to prevent the Emperor from winning