The first stage of Napoleon’s 1815 campaign was to concentrate the 123,000 men of his Armée du Nord just south of the junction of the Duke of Wellington’s 112,000 Anglo-Dutch Army and Prince Gerbhard von Blücher’s 130,000 Prussians.
Napoleon’s plan was to position his army between his two enemies, preventing them uniting. He would then defeat one of them, making it retreat along its line of supply and leaving it unable to support its ally, which Napoleon could then turn on.
The Emperor had an experienced army with high morale. but he made a number of ‘unsuitable appointments’ to high command. His long serving chief of staff, Marshal Louis-Alexandre Berthier, had fallen from a window to his death on 1 June: whether this was an accident, murder or suicide has never been resolved. However, Napoleon had already given this job to Marshal Jean-de-Dieu Soult, an experienced battlefield commander who had never held such a position. The best choice would have been Marshal Louis-Gabriel Suchet, who was instead commanding the Army of the Alps.
Command of the left wing was given to Marshal Michel Ney, a very brave and inspiring leader, but unsuited to independent command. Emmanuel de Grouchy, a fine cavalry commander with little experience of infantry, was promoted to Marshal after the battle of Ligny on 16 June and put in command of the right wing. Marshal Louis-Nicholas Davout, Napoleon’s best Marshal, was left in Paris as its Governor and Minister of War. Davout on the right and Soult on the left were Napoleon’s best options for wing commanders.
The Emperor also declined to employ Joachim Murat, King of Naples, the best cavalry commander of the Napoleonic Wars. He had good reasons to do so: Murat had defected to the enemy in 1814 and then attacked the Austrians in Italy too soon in 1815. His consequent rout at Tolentino on 2-3 May allowed the Austrians to redeploy troops from Italy to France. Grouchy would have been a good alternative, but Napoleon did not appoint an overall cavalry commander.
Wellington’s army was a multi-national one, including Dutch and Belgians from the Netherlands army and a large number of Germans, including men from Brunswick, Hannover and Nassau, plus the King’s German Legion, who were Germans in British service. The quality of Wellington’s troops was mixed. Some were veterans, whilst others were inexperienced conscripts. Many of the veteran British troops and commanders had been sent to North America to fight in the War of 1812. Major-General John Lambert, who had taken over command at New Orleans after his superiors were killed or wounded, returned home in time to also fight at Waterloo, but many others were still in or on the way home from North America. The veteran Dutch-Belgians had obtained their experience fighting for Napoleon.
One of Wellington’s corps commanders was the very experienced British General Sir Rowland Hill but the other was the very inexperienced 22 year old Prince of Orange. His second in command and cavalry commander was the Earl of Uxbridge. He was a much better cavalry general than Wellington had had for most of the Peninsular War, but their personal relations were poor, since Uxbridge had eloped with Wellington’s sister-in-law. The army did have good division commanders, both British and Germans who had gained their experience fighting against Napoleon and Dutch and Belgians who had fought for him.
Over half of Blücher’s army consisted of Landwehr, who were inexperienced and poorly equipped but often highly patriotic. There were also a number of men from parts of Germany that only became Prussian in 1814, many of whom had fought for Napoleon until then. They included 14,000 Saxons and Silesians who mutinied and had to be disarmed before the campaign even began.
The French began to move at 2:30 am on 15 June, taking Blücher and ‘especially’ Wellington by surprise. The Duke and many of his senior officers were attending the Duchess of Richmond’s ball in Brussels on the evening of 15 June.
About 2 pm on 15 June General Jean Victor de Constant Rebecque, the Prince of Orange’s chief of staff, authorised General Count Perponcher-Sedlnitzberg, commander of the 2nd Dutch-Belgian Division, to move Prince Bernhard of Saxe-Weimar’s brigade of Nassauers to the crossroads at Quatre-Bras, a vital junction on the road from Charleroi.
Ney had sent 2,000 cavalrymen under General Charles Lefebvre-Desnouëttes to reconnoitre ahead of the main body of the left wing of the Armée du Nord. They encountered Bernhard’s advance guard, which retired on the rest of his brigade.
At 8 pm Rebecque authorised the other brigade of Perponcher’s division, Dutch-Belgians commanded by the Count of Bylandt, to move from Nivelle to Quatre Bras. Soon afterwards Rebecque received an order sent by Wellington in the afternoon that stated that all of Perponcher’s division should move to Nivelle. Rebecque showed it to Perponcher, saying nothing, and the latter decided to ignore it. 
David Chandler quotes the British general and military historian J. T. Fuller as saying that ‘this act of intelligent insubordination saved Blücher’, adding that it also ‘saved Wellington’s reputation.’ Geoffrey Wootten argues that Perponcher and Bernhard showed ‘the benefits of their French training at Quatre Bras where bold initiative and intelligence – the hallmark of the French approach – were to be critical to Wellington’s survival and eventual success.’
However, Perponcher’s 8,000 infantry, 16 guns and 50 cavalry were faced by Ney’s 25,000 infantry, 3,000 cavalry and 60 guns, with 20,000 more French close behind and another French corps and the Imperial Guard expected.
Reports of the French advance reached Wellington during the ball. He realised that a move by Napoleon towards Mons was a feint to draw his army west in order to protect its line of supply. He told the Duke of Richmond that Napoleon had ‘humbugged me…He has gained 24 hours’ march on me…I have ordered the army to concentrate at Quatre Bras; but we shall not stop him there, and if so, I must fight him here’, pointing to Waterloo on the map.
Napoleon expected Wellington to fall back and had therefore planned to attack him before he could concentrate his army. He told Ney of this verbally, but the exhausted Emperor did not dictate his written orders until 6 am, four hours later than his usual practice. There was a further two hour delay before they left his HQ, and Ney did not receive his written orders until 10:30 am. They told him to ‘hold yourself in readiness for an immediate advance towards Brussels once the Reserve reaches you’ so he issued no orders until 11 am and did not attack until 2 pm, by when Wellington reinforcements were arriving. Wellington reached Quatre Bras at 9:30 am, saw that the French were cooking food and headed to Ligny to meet Blücher.
The attack by General Honoré Charles Reille’s II Corps began at 2 pm. It was initially successful and had broken through the thin defensive line by 3 pm. However, Sir Thomas Picton’s 5th Division then arrived and stabilised the situation. Wootten notes that if ‘Reille had started just a short while earlier…the battle would now have been over almost before it had started.’ The arrival of Picton’s 8,000 men meant that 25,000 French troops were now facing 17,000 defenders.
About 4 pm Ney received a message sent at 2 pm ordering him to attack and drive back whatever force he was facing, before turning to envelop Blücher. However, he did not realise that his sector was now the secondary one: Blücher’s forward disposition had made Napoleon to make the Prussians at Ligny rather than the Anglo-Dutch at Quatre Bras the main target.
Ney sent an aide to hurry the advance of the 20,000 men of the Comte D’Erlon’s I Corps to Quatre Bras. However, the Comte de la Bedoyère, carrying orders to Ney to send I Corps against the Prussian flank encountered I Corps before he met Ney. De la Bedoyère sent it towards Ligny, but an error meant that it headed for the French rather the Prussian flank. Ney was furious when he discovered this; soon afterwards the appearance of another of Wellington’s divisions led him to send a message ordering I Corps back to Quatre Bras. It had nearly reached Ligny when the message arrived; it ended up fighting in neither battle.
At 4:15 pm British squares beat off an attack by French lancers at the expense of heavy casualties. More reinforcements were arriving, giving Wellington 26,000 men and 42 guns. At 5 pm Ney ordered General François Étienne de Kellermann to attack with his heavy cavalry, although only one of his four brigades had arrived. The charge almost succeeded, catching two British infantry battalions in line, but it lacked infantry and light cavalry support and was thrown back by fire from a King’s German Legion gun battery and two British infantry battalions.
By 6:30 pm Wellington had 36,000 men and 70 guns, outnumbering Ney. He counter-attacked and by 9 pm had regained almost all the ground lost earlier in the day. Total casualties (dead, wounded, captured and missing) were 4,100 French and 4,850 Coalition, 250 of the latter in the retreat the next day.
The main French attack, however, had been made against the Prussians at Ligny. The Prussian defence was based along the Ligny, a marshy stream that was hard to cross other than at its four bridges. A defensive line based on ten villages and hamlets covered them. The ground rose to the rear. However, the defensive line was vulnerable to flanking fire and troops on the forward slope could be bombarded by artillery. Napoleon intended to demonstrate with cavalry on the Prussian left whilst attacking their right and centre. When Ney appeared on their right the Guard would destroy the Prussian centre.
The Prussians had 84,000 men, including 8,000 cavalry, and 224 guns to defend seven miles. Despite the favourable terrain, this was too few to defend that distance: 20,000 men per mile were then believed to be needed in defence. The Prussians hoped that a further 31,000 of their troops plus Wellington’s force would support them, but the former were too far away and the latter too heavily engaged. The French had 68,000 infantry, 12,500 cavalry and 210 guns, but could choose where to concentrate their attack and expected support from Ney.
The attack began at 2:30 pm. Napoleon assumed that Ney had taken Quatre Bras and was heading for Ligny, since no gunfire had been heard from that direction.
Grouchy’s cavalry on the French right pinned the Prussian left. A fierce battles for the Ligny stream and the villages beside it took place in the centre and on the Prussian right, French left. The Prussian reserve infantry was drawn up close enough to the line to be bombarded by French artillery, but too far away to use their muskets to support their front line.
At 3:15 pm Napoleon sent an order telling Ney to envelop the Prussian right and rear. Almost immediately, he received news of Quatre Bras, so ordered that only D’Erlon’s I Corps should move to Ligny. Shortly afterwards, he realised that he had left the 10,000 men of the Comte de Lobau’s VI Corps near Charleroi without any orders, so ordered them to Ligny.
By 5 pm Blücher had been forced to commit virtually all his reserves, but Napoleon still had 10,000 fresh troops. He intended to launch his Imperial Guard at 6 pm to strike the decisive blow, but about 20,000 men then appeared on the French left flank, causing the French troops there to waver. At first they were assumed to be hostile, but by 6:30 pm it was apparent that they were the French I Corps in the wrong place. D’Erlon had failed to follow the normal practice of sending officers ahead of his force. Napoleon ordered him to the correct place on the Prussian right flank, but by the time that the messenger arrived I Corps was on its way back to Quatre Bras.
Blücher now led personally a counter attack by six battalions, which briefly retook the village of St Amand, but the French rallied and recaptured it. The Guard finally attacked at 7:30 pm in heavy rain. The infantry was supported by 60 guns on their right and heavy cavalry. Blücher then led another counter attack, this time by 32 squadrons of cavalry. It was repulsed and his horse was killed. French cavalry rode over him without recognising him, and he was eventually rescued by an aide. The Prussian centre had been crushed, but both wings were able to withdraw under cover of darkness.
Total dead, wounded, missing and captured at Ligny were 13,700 French and 18,800 Prussians, with another 120 French and 10,000 Prussians being lost in the retreat the next day.
Napoleon had defeated Blücher at Ligny, but the Prussians had escaped to fight again. Wellington and Ney had drawn at Quatre Bras, but the Anglo-Dutch army was forced to retreat because of the result of Ligny. If D’Erlon’s corps had fought at either battle, it would have been a decisive French victory. If Reille had attacked earlier, Ney could have won Quatre Bras soon enough to arrive on Blücher’s flank and make Ligny a decisive victory. These mistakes were Napoleon’s fault for making the wrong appointments.
 M. Adkin, The Waterloo Companion (London: Aurum, 2001), p. 29.
 G. Wootten, Waterloo 1815: Birth of Modern Europe (London: Osprey, 1992), p. 29.
 D. Chandler, The Campaigns of Napoleon (London: Weidenfeld & Nicolson, 1966), p. 1023.
 The last three paragraphs are based on Ibid., pp. 1021-22.
 Wootten, Waterloo, pp. 21-23.
 Ibid., pp. 16-17.
 Chandler, Campaigns, p. 1027.
 The last three paragraphs are based on Ibid., pp. 1030-32.
 Ibid., p. 1032.
 Wootten, Waterloo, pp. 15-16.
 Ibid., p. 31.
 Chandler, Campaigns, pp. 1032-33.
 Wootten, Waterloo, pp. 31-32.
 Ibid., p. 32.
 Chandler, Campaigns, p. 1050.
 Ibid., pp. 1040, 1050.
 Ibid., pp. 1051-52.
 Ibid., pp. 1052-53.
 Adkin, Waterloo, p. 74.
 Wootten, Waterloo, p. 40.
 Chandler, Campaigns, p. 1038.
 Wootten, Waterloo, p. 40.
 Chandler, Campaigns, p. 1041.
 Ibid., p. 1043.
 Ibid., pp. 1044-45.
 Ibid., pp. 1045-46.
 Adkin, Waterloo, p. 74.