Prince William may now be the heir apparent to the throne, but he's not the Queen's only grandchild. In fact, Queen Elizabeth had eight grandkids (not to mention twelve great-grandchildren, including newest additions Sienna Elizabeth Mapelli Mozzi and Lilibet Diana Mountbatten-Windsor).
On the Saturday before her funeral, all eight will stand vigil beside her coffin in Westminster Hall. Per Buckingham Palace, Prince William will stand at the head, flanked by his cousins Zara Tindall and Peter Phillips; Prince Harry will stand at the foot, flanked by Princesses Beatrice and Eugenie, with the Queen's youngest grandchildren, Lady Louise, and James, Viscount Severn at the middle of the coffin. Both Harry and William will be in uniform, "at the King's request."
Per the Palace, "The grandchildren, at the King's invitation, are very keen to pay their respects—just as their parents are doing the evening before."
Below, are all of the Queen's granddaughters and grandsons from oldest to youngest, plus, how they're related to the late British monarch.