The virtually complete destruction of the British Fleet in the Battle of Trafalgar on October 21, after the fateful shot that killed Admiral Nelson, forced the British to retreat, opening the way for the French to invade England. However, Napoleon, not wishing to invade and conquer the "island of shopkeepers", instead offered an olive branch, accepting peace in return for trading privileges for both sides. Prime Minister William Pitt the Younger accepted, and the Peace of Copenhagen was signed.