The Queen celebrates her 91st birthday today and is expected to spend the anniversary privately.
After her 90th birthday last year, which saw national festivities held in her honour, the 2017 milestone will seem more subdued.
But royal gun salutes will still echo across the capital later, fired by the King’s Troop Royal Horse Artillery and the Honourable Artillery Company.
In Hyde Park at midday, 41 volleys in honour of her birthday will be fired by the King’s Troop Royal Horse Artillery.
Then an hour later the Honourable Artillery Company will fire a 62-gun salute at the Tower of London – an extra 21 for the City of London.
The Queen traditionally has two birthdays, her actual birthday and an official birthday marked every summer by the Trooping the Colour ceremony. The curious decision to give monarchs two birthdays dates back to Edward VII, who was born on November 9 but celebrated the birthday in May and June as the weather was better during these months for outdoor events.
Subsequent monarchs helpfully had birthdays at more convenient times of the year, but the Queen’s father, King George VI, reintroduced the tradition which she has continued.
From the Telegraph, April 21, 2017