By the time it was passed, Prince Charles was the father of two children who have overtaken his other siblings in the line of succession.
Princess Anne is currently 14th in line to the British throne.
While it is unlikely she will become Queen, she is often considered one of the hardest working royals.
She also has a close relationship with her mother, according to body language expert Judi James.
She told Express.co.uk: “Like her father, Anne appears to make the Queen laugh and most poses between the two women suggest a shared sense of humour, bringing out a side of the Queen that we rarely get to glimpse.