Military history of Spain Portugal and engage French forces on the frontiers while Spanish "guerrilleros" wore down the occupiers. Acting in concert, regular and irregular allied forces prevented Napoleon's marshals from subduing the rebellious Spanish provinces. The Spanish navy, put to sea in support of France during the War of the Third Coalition in 1805, suffered terrible losses at the Battle of Trafalgar, having been weakened by yellow fever in the preceding years; in many ways this marked the nadir of Spanish naval history. The events in mainland Spain had extensive consequences for her empire. Spain's colonies in the Americas had shown an increasing
Coalition forces of the Napoleonic Wars 300,000; and Russia, 600,000. 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