Princess Beatrice and Princess Eugenie attended Sir Elton John's prestigious ball with their mother Sarah Ferguson, the Duchess of York.

Princess Beatrice wore a nude Elie Saab net and flower gown

Source: http://www.redcarpet-fashionawards.com/2011/06/24/princess-beatrice-in-elie-saab-couture-13th-annual-white-tie-and-tiara-ball-to-benefit-elton-john-aids-foundation/

Vivienne Westwood's dress worn by Princess Eugenie

Read more: http://www.dailymail.co.uk/tvshowbiz/article-2007504/Well-suits--Princess-Eugenie-recreates-Ascot-success-red-gown-Elton-Johns-White-Tie-Tiara-Ball.html