Britain's Camilla, Duchess of Cornwall (L) and Britain's Catherine, Duchess of Cambridge (2nd L) arrive in a horse-drawn carriage at Horse Guards Parade for the Queen's Birthday Parade, 'Trooping the Colour', in London on June 11, 2016. Trooping The Colour and the fly-past are part of a weekend of events to celebrate the Queen's 90th birthday. / AFP PHOTO / OLI SCARFF