Prince Harry and Prince William have come together several times in the wake of their grandmother, Queen Elizabeth II's, death to honor the late monarch in a series of public and private ceremonies. The state funeral procession for Her Majesty on Monday called upon the memory of another significant royal's death — the siblings' mother, the late Princess Diana. ET spoke with royal biographer Andrew Morton at Methodist Central Hall Westminster in England on Monday and discussed Harry and William's notorious rift, and how he feels their mother would react. «Well, the one thing that she would be really furious about is that they had this split,» Morton began, explaining that he had previously discussed the boys' relationship with Diana herself. «She always said to me, not just once, but on several occasions, that Harry is William's backup in the nicest possible way, he's his wingman, he's the one who helps William in this difficult job that he will have in the future because it's a lonely job.