From the age of 6, Princess Margaret was destined to live in the shadow of her older sister.
It was then that their father, Albert, became King George VI when his older brother,Edward VIII, gave up the throne after less than a year as king to marry the twice-divorced American socialite Wallis Simpson. They became the Duke and Duchess of Windsor, and the scandal resulted in 10-year-old Princess Elizabeth becoming the future Queen of England.
The shake-up also vaulted Margaret from fourth to second in line, though she presumably never thought much of it because any children of Elizabeth's would automatically precede her. But though she herself would never wear the crown, generations upon generations of royal protocol still prevented her life from ever being entirely her own.
Which isn't to say that she didn't enjoy herself.