When she was born at Kensington Palace on May 1, 1964, she was seventh in the line of succession. Weighing 6lb and 2oz, this was the last royal to be born in a palace, not a hospital.
Lady Sarah Chatto, who turns 59 today, is the only daughter of the Princess Margaret and Antony Armstrong-Jones. She had a particularly close relationship with the late Queen Elizabeth.
The Queen s only niece, who has remained close to Her Majesty and Prince Philip for many years, joined other members of the royal family today to celebrate the life of the Duke of Edinburgh.