Earlier in the day, the Queen, who wore a Stewart Parvin ensemble, issued a statement expressing sorrow over the "terrible tragedies" in London and Manchester over the last few weeks.
The interesting fact is that her Majesty's actual birth date is April 21, but the grand military parade is rather an extravagant way of celebrating each British monarch's official birthday.
Putting aside thoughts of her anniversary, marked with the pomp and pageantry of the Trooping the Colour ceremony, the head of state said everyone was "determined" to support all those rebuilding their lives. This year, however, it is hard to escape a very' sombre national mood.
Members of Britain's Royal family from left, Camilla, the Duchess of Cornwall, Prince Charles, Princess Eugenie, Queen Elizabeth II, background Timothy Laurence, Princess Beatrice, Prince Philip, Kate, the Duchess of Cam.
The Queen continued: "Put to the test, the United Kingdom has been resolute in the face of adversity".
Dressed in his full uniform - including a bearskin - one soldier fell forward out of his formation at the Horse Guards Parade at St Jame's Park marking the Queen's official birthday.