Images of Britain's Prince William and his girlfriend Kate Middleton are seen on a proposed souvenir wedding mug designed by, the then, high street retailer Woolworths, in this undated file image released in London on November 17, 2006.[Photo/Agencies]

The girlfriend of Britain's Prince William, Kate Middleton, is seen attending the Cheltenham horse racing Festival in Gloucestershire, western England in this March 16, 2007 file photograph.[Photo/Agencies]