King George III was a great and influential leader. He was the King of Great Britain and led them during the American Revolution. King George III was one of the longest reigning British Monarchs. He oversaw the conquest of an empire in the Seven Years' War, and the loss of the American Colonies in the War of Independence. The British Empire was the leading model of Industrial and economic development in an era when the whole world was to be mapped and conquered. The face of Europe changed dramatically, as Britain and France struggled for domination. Britain emerged from that struggle as the world's leading power, but it was a nation faced with a fragile governmental structure and deep social strife.