Prince Harry, Meghan Markle caused queen stress in final years: author Hugo Vickers, author of "Queen Elizabeth II: A Personal History," details how the Duke and Duchess of Sussex's exit and Oprah interview added strain during the late monarch's final years. NEW You can now listen to Fox News articles! Queen Elizabeth II’s fiercest protector, who earned the nickname "AK-47," would "take a bullet" for the monarch, royal experts claimed. This devotion later put her on a collision course with