They were close sisters and best friends. But the abdication of the crown by their uncle Edward VIII changed once and for all the once strong and trusting relationship between Elizabeth and Margaret. Now they are separated by a "squad of secretaries opening doors." Margaret is forced to name her sister Your Highness instead of the affectionate "Lilibet." And for Elizabeth, Margot's seemingly hilarious antics are increasingly becoming a source of tension. Royal biographer Andrew Morton presents the first detailed biography of two of the world's most celebrated sisters, revealing details of their relationship - from the idyll of their solitary childhood to the different fates that were intended for them after the death of their father and the accession of Elizabeth to the throne. This documentary book is based on the testimony of those close to the Windsor family, former palace assistants, as well as insiders who have known Elizabeth and Margaret over the years.