The monarch's birthday is celebrated annually with the Trooping the Colour parade and this year will see King Charles take centre stage at the event for the first time. The new King will be riding on horseback during the event, something that hasn't happened since 1986.
The parade marks the King's birthday, although Charles was actually born on 14 November, it's traditional for the monarch if born in the colder, winter months, to celebrate in summer when the weather is likely to be better.
Last year was the final Trooping the Colour parade of the late Queen Elizabeth's 70-year reign, and also formed part of her Platinum Jubilee celebrations.
The official date of the late Queen Elizabeth's jubilee was February 6, but Platinum Jubilee celebrations were held off until her official birthday weekend in June, as 6 February also marks the anniversary of her father’s death as she ascended the throne when King George VI died in 1952.
During the coronavirus pandemic, the parade had to be cancelled in its usual form and the Queen saw a pared-back version at the Quadrangle of Windsor Castle.
2022, however, saw a return to form for the annual set piece event, with the senior royals appearing on the balcony to view a flypast.
As Charles readies himself for his first official birthday as monarch, Yahoo UK looks back at the best moments from Trooping the Colour during Queen Elizabeth's reign, and her life as Princess Elizabeth.