Princess Margaret was the younger sister of Queen Elizabeth.
She was born Margaret Rose on 21 August 1930, at Glamis Castle in Scotland.
She was the first royal born in Scotland since the seventeenth century.
Her parents were the Duke and Duchess of York at the time. But in 1936 the King, Edward VIII, announced he was giving up his crown.
This meant Margaret's father had to take over and her life had to change.
From 1937, when Margaret was enrolled as a Brownie in the Buckingham Palace Pack (see picture above), the Girl Guide movement became an important part of her life.
She later became the association's president.