Prince William and Prince Harry have suffered a fresh heartbreak after their uncle died at the age of 82. Lord Robert Fellowes was married to Princess Diana’s sister, Lady Jane Fellowes, for 46 years. He also worked as Queen Elizabeth II’s private secretary for nine years during the 1990s. Lord Fellowes died of undisclosed causes on July 29. The British courtier was the late monarch’s most important adviser during the divorces of three of her children and the late Princess of Wales’s death in 1997. In 1978, Lord Fellowes married Lady Jane Spencer, the elder sister of Diana, who was a bridesmai…