Britain's Queen Elizabeth II and Prince Philip attend a National Service of Thanksgiving to mark the 90th birthday of Britain's Queen Elizabeth II at St Paul's Cathedral in London, Friday, June the 10th, 2016.
Later on in the day, the Queen joined other members of the Royal Family on the Buckingham Palace balcony for an RAF fly-past.
The queen, wearing a lime green outfit visible from the farthest points of the crowded Mall, travelled by horse-drawn carriage, sometimes waving to the throng.
Royal commentator Richard Berthelsen told CTV News Channel that the lunch is focused on grassroots organizations that the Queen supports through her royal patronage.
This year's parade has added significance, though as it takes place during three days of commemorations to celebrate The Queen's milestone birthday.
Armed forces personnel before the royal procession make its way down The Mall from Buckingham Palace, central London to Horse Guards Parade for the Trooping the Colour ceremony as the Queen celebrates her official birthday today.
The splendid Trooping the Color parade, which featured more than 1,500 soldiers and officers, also included a fly-by of historic World War II aircraft and modern fighter planes.
Why? Colour tradition originates from preparations for battle when flags were carried or "trooped" down the rank for soldiers to see.