Why does The Queen have two Birthdays?

The Queen has two birthdays every year: one on her actual birthday, on 21 April, and the other in June, marked with Trooping the Colour on Horseguards Parade. The tradition goes back more than a hundred years to the reign of The Queen’s great-grandfather, Edward VII, who was King from 1901 to 1910. Edward was born in November and decided that the English weather in November was not ideal for royal parades – especially so because the London fog a century ago was the notorious "pea-souper", so thick at times that people could barely see where they were going, let alone watch the troops march by.

The tradition goes back more than a hundred years to the reign of The Queen’s great-grandfather

George V, Edward VII’s son, was born in the summer so reverted to a single birthday celebration, but his son, George VI, the present Queen’s father, was born mid-December, so he revived the idea of the Sovereign having an official summer birthday in mid-June. When The Queen came to the throne in 1952 she was only twenty-five and her instinct was to follow her father’s example in almost everything – including having her official birthday in June.

Prince Charles, born in November, will almost certainly continue the tradition when the time comes, but Prince William was born on 21 June and Prince George was born on 21 July, so, in the longer term, who knows what the future holds?

Gyles will share more of his historical insight during BBC One's live coverage of The Queen's 90th Birthday, at The National Service of Thanksgiving and The Patron's Lunch.