According to The Crown’s resident royal historian, Robert Lacey, Princesses Beatrice and Eugenie may become more active participants of the royal family following the exit of the Duke and Duchess of Sussex.“If two go out, two have got to come in, and those two have got to be Beatrice and Eugenie,” Lacey told Hello! magazine. The Crown's go-to royal historian, Robert Lacey, has a theory of who could step in for the Duke and Duchess of Sussex's royal duties.