It's been said before Britain's main power was its navy. The British army was small and far flung. It was a volunteer force made up mostly of the poor hoping to better their condition. In 1775, it only numbered 40,000 men. This is why they had to hire Prussian mercenaries during the American Revolutionary War. In comparison, the French army of the time was four times larger. Even by 1802, the entire British army was only 120,000 men. At its peak in 1812, France's Grande Armėe numbered over one million. The British had 250,000 men at that time. They could only challenge Napoleon with alliances.