The Coalition forces of the Napoleonic Wars were composed of Napoleon Bonaparte's enemies: the United Kingdom, the Austrian Empire, Kingdom of Prussia, Kingdom of Spain, Kingdom of Naples, Kingdom of Sicily, Kingdom of Sardinia, Dutch Republic, Russian Empire, the Ottoman Empire, Kingdom of Portugal, Kingdom of Sweden, and various German and Italian states at differing times in the wars. At their height, the Coalition could field formidable combined forces of about 1,740,000 strong. This outnumbered the 1.1 million French soldiers. The breakdown of the more active armies are: Austria, 570,000; Britain, 250,000; Prussia, 300,000; and Russia, 600,000.
British Forces
The British Army forces consisted of 250,000 troops at their height. This is notable as it consisted of 2% of the entire British population during that time. Integral divisions of the British army were the King's German Legion (18,000 men), the Brunswick troops, and several other troops from France, Switzerland and the Netherlands. While Great Britain played a major role in various campaigns on land, at sea the Royal Navy was the dominant part of the allied naval power, and succeeded in destroying French naval power in a series of major sea battles culminating in the Battle of Trafalgar in 1805.
Infantry
Gaining experience under the Duke of Wellington in the Peninsular War and forged into a disciplined, honed weapon of war, they advanced to become a prominent force in the Napoleonic Wars. The redcoats, as they were called, principally employed tactics such as disciplined platoon fire and (sometimes) bayonet charges and saw much success through these methods.
These foot soldiers were typically equipped with the tower-pattern musket, or 'Brown Bess', whose inaccuracy was compensated by the technique of mass firing by platoons.
Light infantry
The British and German elite light infantry held a distinct advantage over their counterparts on the battlefield as they were equipped with Baker rifles. Having grooved barrels, these rifles achieved great target accuracy over a considerable distance and in this respect were superior to the muskets used by the French voltigeurs. Napoleon Bonaparte's rationale for choosing to equip his soldiers with muskets was their faster loading speed, a decision not without consequence for battlefield strategy. The British and German light battalions were deployed in pairs of two soldiers, forming a skirmish curtain, fighting quite independently and using all the cover they could find. These were new tactics, frowned on by more conservative officers, but very effective against enemy officers, who were often the first targets of the fights.
Line infantry
The line, column, and square formations were the most recognised tactical formations in use during the Napoleonic era. Each of these formations had its own unique purpose in attacking or counter-attacking and no doubt played a large role in battlefield tactics. The line formation was the most favoured amongst the British infantry. Lined up in this way, all men were able to fire at the same time, reaching a maximum firepower of about 1000 to 1500 bullets per minute. The column formation, favoured by the French, was unable to achieve any such output since only the men in the first row of the column (about 60) were able to fire their rifles at once. While the line formation worked well in engagements with infantry, it was very vulnerable whenever the enemy employed cavalry to attack the formation from the rear or at force, causing chaos and horrendous casualties. In the event of cavalry involvement, battalions would therefore hasten to reorganise their lines to square formation to cover their back against a much more mobile force.
The square formation seems to have been the best protection against cavalry as horses were very reluctant to push into a row of bayonets three or more lines deep. We know of only a few battles during which square formations were overrun by cavalry, one being the Battle of Salamanca, during which three French squares were broken up by the King's German Legion's heavy dragoons.