Something went wrong, please try again later. Invalid email Something went wrong, please try again later. Prince William’s nickname has been revealed in brother Harry's new book. The Duke of Sussex shared William's nickname in Spare, his forthcoming memoir. William is known by Harry as 'Willy', the 38 year old has written. The Prince of Wales calls Harry “Harold” while the duke calls William “Willy”, he admitted. In a row over Meghan Markle, Harry claims he told his older brother: "Willy, I can’t speak to you when you’re like this." After an attack in Nottingham Cottage, William reportedly denied it...