Elizabeth Alexandra Mary was born on this day, April 21, in 1926. She was the first child of the Duke and Duchess of York, later King George VI and Queen Elizabeth.  When her father died in February 1952, she became head of the Commonwealth and queen regnant of seven independent Commonwealth countries: the United Kingdom, Canada, Australia, New Zealand, South Africa, Pakistan and Ceylon.

Karsh photographed King George VI and Princess Elizabeth in 1943, and would return to photograph Her Royal Highness, and her family, on several occasions.  See them here.