Britain’s Prince Philip, Duke of Edinburgh and husband of Queen Elizabeth II, has died at the age of 99, Buckingham Palace announced today. The palace said in a statement that Prince Philip passed away peacefully this morning at Windsor Castle. Further announcements will be made in due course and the Royal family join with people around the world in mourning his loss, it also said. The Duke of Edinburgh, as he was officially known, had been by his wife’s side throughout her 69-year reign, which is the longest in British history. They married in 1947.