The British monarch, who was diagnosed with an undisclosed form of cancer earlier this year, will be attending Trooping the Colour on Saturday. This event marks the second in his reign and the first since his diagnosis was made by Buckingham Palace.
According to royal biographer Christopher Andersen, the tradition of the monarch having two birthday celebrations dates back to King Charles II and Trooping the Colour became an annual event during the reign of King George III.
