Napoleon BonaparteMarquis de GrouchyMarshal SoultMarshal Davout all at different times commander of  L'Armée du Nord
 Jean Rapp (Armée du Rhin)
 Suchet, Duc d'Albuféra (Armée des Alpes)
 Claude Lecourbe (Armée du Jura)
 Guillaume Brune Armée du Var
 During the Hundred Days of 1815, both the Coalition nations and the First French Empire of Napoleon Bonaparte mobilised for war. This article describes the deployment of forces in early June 1815 just before the start of the Waterloo Campaign and the minor campaigns of 1815.
 Upon assumption of the throne, Napoleon found that he was left with little by the Bourbons and that the state of the Army was 56,000 troops of which 46,000 were ready to campaign. By the end of May, the total armed forces available to Napoleon had reached 198,000 with 66,000 more in depots training up but not yet ready for deployment.
 By the end of May, Napoleon had deployed his forces as follows:
 The preceding corps were to be formed into L'Armée du Nord (the "Army of the North") and led by Napoleon Bonaparte would participate in the Waterloo Campaign.
 For the defence of France, Bonaparte deployed his remaining forces within France observing France's enemies, foreign and domestic, intending to delay the former and suppress the latter. By June, they were organised as follows:
 V Corps – Armée du Rhin (Rapp), cantoned near Strassburg.
 VII Corps – Armée des Alpes (Suchet). Based at Lyons, this army was charged with the defence of Lyons and to observe the Austro-Sardinian army of Frimont. Its composition in June was:
 I Corps of Observation – Armée du Jura Based at Belfort and commanded by General Claude Lecourbe, this army was to observe any Austrian movement through Switzerland and also observe the Swiss army of General Bachmann. Its composition in June was:
 II Corps of Observation – Armée du Var. Based at Toulon and commanded by Marshal Guillaume Marie Anne Brune, this army was charged with the suppression of any potential royalist uprisings and to observe General Bianchi's Army of Naples. Its composition in June was:
 III Corps of Observation – Army of the Pyrenees orientales. Based at Toulouse and commanded by General Charles Mathieu Isidore Decaen, this army observed the eastern Spanish frontier. Its composition in June was:
 IV Corps of Observation – Army of the Pyrenees occidentales. Based at Bordeaux and commanded by General Bertrand Clauzel, this army observed the western Spanish frontier. Its composition in June was:
 Army of the West  – Armée de l'Ouest  (also known as the Army of the Vendée). Commanded by General Jean Maximilien Lamarque, the army was formed to suppress the Royalist insurrection in the Vendée region of France, which remained loyal to King Louis XVIII during the Hundred Days. The army contained line units as well as gendarmes and volunteers. Its composition in June was:
 Total 10,000–27,000 men.
 The Seventh Coalition armies formed to invade France were:
 The forces at the disposal of the Seventh Coalition for an invasion of France amounted to the better part of a million men. According to the returns laid out in secret sittings at the Congress of Vienna the military resources of the European states that joined the coalition, the number of troops which they could field for active operations—without unduly diminishing the garrison and other services in their respective interiors—amounted to 986,000 men. The size of the principal invasion armies (those designated to proceed to Paris) was as follows:
 Cantoned in the southern part of the Kingdom of the Netherlands, in what is now Belgium, Field Marshal Arthur Wellesley, 1st Duke of Wellington commanded a coalition army, made up of troops from the duchies of Brunswick, and Nassau and the kingdoms of Hanover, the Netherlands and the United Kingdom.
 In June 1815 Wellington's army of 93,000 with headquarters at Brussels was cantoned:
 The Netherlands Corps, commanded by Prince Frederick of the Netherlands did not take part in early actions of the Waterloo Campaign (it was posted to a fall back position near Braine), but did besiege some of the frontier fortresses in the rear of Wellington's advancing army.
 A Danish contingent known as the Royal Danish Auxiliary Corps commanded by General Prince Frederick of Hessen-Kassel and a Hanseatic contingent (from the free cities of Bremen, Lübeck and Hamburg) later commanded by the British Colonel Sir Neil Campbell, were also on their way to join this army, both however, joined the army in July having missed the conflict.
 Wellington had very much hoped to obtain a Portuguese contingent of between 12,000 and 14,000 men that might be boarded on ships and sent to this army. However, this contingent never materialised, as the Portuguese government were extremely uncooperative. They explained that they did not have the authority to send the Prince Regent of Portugal's forces to war without his consent (he was still in Brazil where he had been in exile during the Peninsular War and had yet to return to Portugal). They explained this even though they themselves had signed the Treaty of 15 March without his consent. Besides this, the state of the Portuguese army in 1815 left much to be desired and were a shadow of their former self with much of it being disbanded.
 The Tsar of Russia offered Wellington his II Army Corps under general Wurttemberg, but Wellington was far from keen on accepting this contingent.
 This army was composed entirely of Prussians from the provinces of the Kingdom of Prussia, old and recently acquired alike. Field Marshal Gebhard Leberecht von Blücher commanded this army with General August Neidhardt von Gneisenau as his chief of staff and second in command.
 Blücher's Prussian army of 116,000 men, with headquarters at Namur, was distributed as follows:
 This army was part of the Prussian Army above, but was to act independently much further south. It was composed of contingents from the following nations of the German Confederation: Electorate of Hessen, Grand Duchy of Mecklenburg-Schwerin, Grand Duchy of Mecklenburg-Strelitz, Grand Duchy of Saxe-Weimar-Eisenach, Grand Duchy of Oldenburg, Duchy of Saxe-Gotha-Altenburg, Duchy of Anhalt-Bernburg, Duchy of Anhalt-Dessau, Duchy of Anhalt-Kothen, Principality of Schwarzburg-Rudolstadt, Principality of Schwarzburg-Sondershausen, Principality of Waldeck and Pyrmont, Principality of Lippe and the Principality of Schaumburg-Lippe.
 Fearing that Napoleon was going to strike him first, Blücher ordered this army to march north to join the rest of his own army. The Prussian General Friedrich Graf Kleist von Nollendorf initially commanded this army before he fell ill on 18 June and was replaced temperately by the Hessen-Kassel General von Engelhardt (who was in command of the Hessen division) and then by Lieutenant General Karl Georg Albrecht Ernst von Hake. Its composition in June was:
 Total 25,000
 Field Marshal Michael Andreas Barclay de Tolly commanded the First Russian Army. In June it consisted of the following:
 Total 200,000
 The Austrian military contingent was divided into three armies. This was the largest of these armies, commanded by Field Marshal Karl Philipp, Prince of Schwarzenberg. Its target was Paris. This Austrian contingent was joined by those of the following nations of the German Confederation: Kingdom of Bavaria, Kingdom of Württemberg, Grand Duchy of Baden, Grand Duchy of Hesse (Hessen-Darmstadt), Free City of Frankfurt, Principality of Reuss Elder Line and the Principality of Reuss Junior Line. Besides these there were contingents of Fulda and Isenburg. These were recruited by the Austrians from German territories that were in the process of losing their independence by being annexed to other countries at the Congress of Vienna. Finally, these were joined by the contingents of the Kingdom of Saxony, Duchy of Saxe-Coburg-Saalfeld, Duchy of Saxe-Meiningen and the Duchy of Saxe-Hildburghausen. Its composition in June was:
 This army was composed entirely of Swiss. The Swiss General Niklaus Franz von Bachmann commanded this army. This force was to observe any French forces that operated near its borders. Its composition in July was:
 Total 37,000
 This was the second largest of Austria's contingents. Its target was Lyons. General Johann Maria Philipp Frimont commanded this army. Its composition in June was:
 Total 50,000
 This was the smallest of Austria's military contingents. Its targets were Marseilles and Toulon. General Frederick Bianchi commanded this army. This was the Austrian army that defeated Murat's army in the Neapolitan War. It was not composed of Neapolitans as the army's name may suggest and as one author supposed. There was however a Sardinian force in this area forming the garrison of Nice under Giovanni Pietro Luigi Cacherano d'Osasco which may have been where the other part of this misunderstanding had arisen. Its composition in June was:
 Total 23,000
 This was Great Britain's smaller military expedition. It was composed of British troops from the garrison of Genoa under General Sir Hudson Lowe transported and supported by the Mediterranean Fleet of Lord Exmouth to Marseilles to aid a French Royalist uprising. The British landed about 4,000 men in Marseilles, made up of soldiers, marines and sailors.
 It was planned that a Spanish army was to invade France via Perpignan and Toulouse. General Francisco Javier Castanos, 1st Duke of Bailen commanded this army.
 It was planned that a second Spanish army was to invade France over the river Bidassoa and into France via Bayonne and Bordeaux. General Henry Joseph O'Donnell, Count of La Bisbal commanded this army.
 Both Wellington's Despatches and his Supplementary Despatches show that neither of the Spanish armies contained any Portuguese contingents nor were they likely too, (See the section Portuguese contingent below), however both Chandler and Barbero state that the Portuguese did send a contingent.
 In order to support the Netherlands field army, plans had been made on 24 May to raise a reserve army. It wasn’t until 19 July until the organisation of the army was laid out: it was to consist of 30 infantry battalions, 18 cavalry squadrons, and four artillery batteries. The infantry was organised from the newly acquired Swiss regiments and newly raised Belgian Militia battalions; the cavalry from the reserves of all nine cavalry regiments, including the colonial hussars and Belgian Militia Carabiniers. By then, the Coalition armies had already set up camp around Paris. The army, existing largely only on paper, was disbanded after three months. Only the 43rd National Militia Infantry Battalion, part of the 4th Infantry Brigade (2nd Infantry Division), was deployed in the observation of Bouillon.
 Commander: Lieutenant-General baron Tindal, Quartermaster / Adjudant-general: Major General D.L. Vermaesen:
 Besides the four Army Corps that fought in the Waterloo Campaign listed above that Blücher took with him into the Kingdom of the Netherlands, Prussia also had a reserve army stationed at home in order to defend its borders.
 This consisted of:
 A Danish contingent known as the Royal Danish Auxiliary Corps commanded by General Prince Frederick of Hessen-Kassel and a Hanseatic contingent (from the free cities of Bremen, Lübeck and Hamburg) commanded by the British Colonel Sir Neil Campbell, were also on their way to join Wellington's army, both however, joined the army in July having missed the conflict.
 Wellington had very much hoped to obtain a Portuguese contingent of 12–14,000 men that might be boarded on ships and sent to this army. However, this contingent never materialised, as the Portuguese government were extremely uncooperative. They explained that they did not have the authority to send the Prince Regent of Portugal's forces to war without his consent (he was still in Brazil where he had been in exile during the Peninsular War and had yet to return to Portugal). They explained this even though they themselves had signed the Treaty of 15 March without his consent. Besides this, the state of the Portuguese army in 1815 left much to be desired and it was a shadow of its former self with much of it being disbanded.
 The Second Russian Army was behind the First Russian Army to support it if required.
 The Tsar of Russia offered Wellington the II Army Corps under General Wurttemberg from his Reserve Army, but Wellington was far from keen on accepting this contingent.