LONDON -- Queen Elizabeth II and her husband Prince Philip have attended a ceremony honoring her birthday.
The parade of horses, soldiers and musicians called "Trooping the Color" is the first official event attended by Philip since he left the hospital last week, following treatment for a bladder infection.
The royal couple rode in a vintage horse-drawn carriage for the parade in central London, where thousands of people turned out to watch the military spectacle.
"Trooping the Color" is an annual ceremony marking the queen's official birthday, which takes place in June. The monarch's actual birthday was on 21 April, when she turned 86.
The ceremony originates from traditional battle preparations, when "colors", which refer to military flags, were carried down the rank to be seen by soldiers.