On 16 June, Napoleon lost his finest chance to win a shattering, decisive victory to rival his destruction of the Prussian army at Jena-Auerstädt in 1806. A communications fiasco resulted in Lieutenant-General Count Drouet d'Erlon's French I Corps marching uselessly to and fro between the Battles of Quatre Bras and Ligny. This wrecked Napoleon's brilliant plan to encircle and trap the bulk of Blücher's army at Ligny, for d'Erlon failed to fall on Blücher's exposed western flank. The incident fully demonstrated that lousy communication was the worst flaw of the French army in 1815.

Napoleon failed to employ Lobau's VI Corps in the fighting of 16 June at either Quatre Bras or Ligny. Lobau would have ensured that the French enjoyed a more advantageous day, but to win a decisive victory it would have had to fall on a flank rather than merely join a frontal attack.

An immediate pursuit of Blücher's army after Ligny is unlikely to have worked unless the Prussians had been more mauled than they in fact were. Napoleon's troops were exhausted, except for the light cavalry on his east wing, and were in no state to undertake night fighting against the tough Prussian rearguard line which only evacuated the battlefield in the early hours of 17 June.

17 June

David Chandler has pointed out that the strategy of the central position, which Napoleon had adopted for this campaign, made it difficult to exploit any victory. An all-out pursuit of one defeated foe was made impossible by the presence of the undefeated second enemy.

Nonetheless, Napoleon would have avoided defeat at Waterloo had he ensured that French cavalry reconnoitred in all directions from Ligny at first light on 17 June. As it was, only light cavalry on the east wing reconnoitred eastwards and no patrols headed north. Proper reconnaissance would have discovered evidence of the retreat of the bulk of the Prussians northwards on Wavre.

This would have permitted Napoleon first, to despatch Grouchy's pursuit in the right direction and second, to take adequate measures to check any Prussian moves towards Waterloo. In particular he would have had time to place Lobau's VI Corps above the formidable Lasne defile two-and-a-half miles east of the battlefield of Waterloo and this would almost certainly have delayed the Prussians until after Wellington suffered defeat. Napoleon would also have known the urgency for commencing the Battle of Waterloo early.

At right, An unusual view of La Belle Alliance, taken from the rear gardens, 1995. © David Watkins

Napoleon's lethargy on the morning of 17 June was fatal. He woke late, then inspected his troops, examined the battlefield of Ligny and discussed the political news from Paris while awaiting information on the situation of his two foes. Had Napoleon been less confident that Wellington as well as Blücher was retreating, he might have ensured that reconnaissances departed in the early hours of 17 June. This would have informed him that Wellington was still at Quatre Bras. Napoleon would then have had an opportunity to fall on Wellington's eastern flank, which the Prussian retreat had uncovered.

Wellington had demonstrated in Spain that he was a master at withdrawing an army in the face of superior numbers. Nonetheless, his army would certainly have suffered considerable casualties and might have been compelled to abandon the Brussels road and fall back north-westwards. Even if Wellington had reached the Waterloo position, Napoleon's forces would have been massed immediately south of it by nightfall ready for battle early in the morning of 18 June.

At the time, Marshal Soult considered that Napoleon was detaching too many troops with Grouchy to pursue Blücher. Soult had no inkling that the Prussians might intervene at Waterloo; he was simply worried that Wellington and his British infantry, whom he had fought in the Peninsular war, would not be easy to overcome. Indeed, after the British heavy cavalry destroyed d'Erlon's I Corps at Waterloo and after Blücher's approach tied down Lobau's VI Corps, Napoleon was desperately short of infantry. Apart from one and a half divisions of II Corps, his only unengaged infantry was in the Guard.

With hindsight, it is clear that Soult was right. Another infantry corps at Waterloo could have helped Napoleon's main attack at 2.00 pm to clear the farms and houses around Papelotte and then to roll up Wellington's far eastern wing. After Waterloo, Napoleon regretted giving so large a force to Grouchy: 'on leaving Quatre Bras, I should have left only Pajol, with [a] ... division of the VI Corps, in pursuit of Blücher, and taken all with me.' [5]

Wellington's British veterans regarded atrocious weather on the eve of battle as a good omen. Indeed, the torrential rain of the afternoon and night of 17 June were a vital reason for Napoleon's defeat at Waterloo. The thunderstorm suddenly turned the Belgian countryside into a quagmire and this greatly hindered the French cavalry pursuing Wellington's rearguard as it retreated from Quatre Bras to Waterloo. The mud meant that Uxbridge's horsemen retreating along the cobbled Brussels road could not be overtaken and cut off by French cavalry moving across the soaked countryside. This contributed to Wellington's remarkably low casualties that day.

The terrible conditions caused by the rain foiled Napoleon's original intention of beginning the battle early in the morning. First he had to postpone the battle to 9.00 am and then again. Firing only began at 11.30 am and the barrage heralding the main attack commenced as late as 1.30 pm. The rain on 17 June had caused many of Napoleon's units to bivouac early, as far south as Genappe, three miles from the battlefield. Many groups of soldiers had wandered away to seek shelter in distant lodgings. Consequently, on 18 June Napoleon did not have his army massed on the battlefield and taking up its positions until 10.00am. This delay was greatly to Wellington's advantage as it gained extra time for Blücher to march to his support.

Footnotes

[3] P. de Callataÿ, 'L'entrée en campagne,' in Waterloo 1815: l'Europe face à Napoléon (1990), pp.29-30
[4] S. de Chair ed., Napoleon's Memoirs (1985), p.551
[5] H. Parker, Three Napoleonic Battles (1983), p.208

Waterloo Continued:

Introduction
15 June to 17 June
18 June
Aftermath