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.

[1] 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.

[24] Based at Toulouse and commanded by General Charles Mathieu Isidore Decaen, this army observed the eastern Spanish frontier.

[24] Based at Bordeaux and commanded by General Bertrand Clauzel, this army observed the western Spanish frontier.

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.

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.

In June 1815 Wellington's army of 93,000 with headquarters at Brussels was cantoned:[37] 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.

[38][39] 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,[40] both however, joined the army in July having missed the conflict.

[51][52] Its composition in June was:[53][54][b] Total 25,000[24] Field Marshal Michael Andreas Barclay de Tolly commanded the First Russian Army.

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.

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.

[60] There was however a Sardinian force in this area forming the garrison of Nice under Giovanni Pietro Luigi Cacherano d'Osasco[61] which may have been where the other part of this misunderstanding had arisen.

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.

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.

This consisted of:[69] 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,[40] both however, joined the army in July having missed the conflict.