General Sir Charles William Pasley KCB FRS (8 September 1780 – 19 April 1861) was a British soldier and military engineer who wrote the defining text on the role of the post-American Revolution British Empire: An Essay on the Military Policy and Institutions of the British Empire, published in 1810. This text changed how Britons thought their empire should relate to the rest of the world. He warned that Britain could not keep its Empire by its "splendid isolation". Britain would need to fight to gain its empire, and by using the colonies as a resource for soldiers and sailors it grew by an average of 100,000 square miles (260,000 km2) per year between the Battle of Waterloo and the American Civil War. Serving in the Royal Engineers in the Napoleonic Wars, he was Europe's leading demolitions expert and siege warfare specialist.