Britain's Prince William rides a horse as he makes his way from Buckingham Palace to attend the Trooping the Colour ceremony in central London June 11, 2011. Trooping the Colour is a ceremony to honour the sovereign's official birthday. [Photo/Agencies]

 
Britain's Catherine, Duchess of Cambridge smiles as she sits in a horse drawn carriage with other members of the royal family as they make their way from Buckingham Palace to attend the Trooping the Colour ceremony in central London June 11, 2011. Trooping the Colour is a ceremony to honour the sovereign's official birthday. [Photo/Agencies]