Video: The Duchess of Cambridge turns heads with glamorous cream dress The Duke and Duchess, who have just celebrated their first wedding anniversary, were guests at a dinner hosted by the elite Thirty Club at Claridge's Hotel in Mayfair, London. The cream, floor-length dress worn by the Duchess had a dramatic split up the front, which showed off her slim legs. It is understood to be by French designer Roland Mouret, although experts speculated it must be a special creation as it had not been seen on the catwalk. Stepping out from her car carefully, she greeted waiting fans with a smile before walking the red carpet into the event. The Royal couple were guests at a private event for the Thirty Club, established more than a century ago and made up of members of advertising and media.