The Queen's Official Birthday, celebrated on the second Saturday of June, marks the third Chapter in our Series
The Queen's Official Birthday was originally celebrated on the second Thursday of June, the same day that her father, King George VI, celebrated his Official Birthday during his reign. However, this was changed in 1959, seven years after she became Queen, and her Official Birthday has since then been celebrated on the second Saturday of June.
The day is marked in London by the ceremony of Trooping the Colour, which is also known as the Queen's Birthday Parade. In British diplomatic missions, the day is treated as the National Day of the United Kingdom. (Wikipedia.org)