London, England (CNN) -- British troops dressed in red jackets and black bearskin hats put on a military spectacle in London on Saturday to mark Queen Elizabeth's official birthday.
They marched to music as other troops sat on horses for the annual ceremony, known as Trooping the Color. It took place on the Horse Guards Parade, the marching ground within sight of the queen's residence at Buckingham Palace.
Queen Elizabeth, wearing a lilac outfit and hat decorated with bow of pink and green, sat front and center to watch what many consider the most celebrated event on the British royal calendar.
The queen, who turned 84 this year, was born on April 21 but celebrates her birthday on a Saturday in June when the weather is better.
Trooping the Color dates at least to the early 18th century, when the colors -- or flags -- of the battalion were "trooped" down the ranks so they could be seen and recognized by all the soldiers, according to Buckingham Palace and the British Army.
