Potential bidders will be vying for a unique piece of royal memorabilia as designer gowns once worn by the late Diana, Princess of Wales, head to the auction block in Toronto. The group of 14 evening dresses are up for sale Thursday night at auction house Waddington's. A woman is shown touring "The Life of Royal Icon" exhibit, a collection of 14 dresses of the late Diana, Princess of Wales, in Toronto on Monday May 16, 2011. THE CANADIAN PRESS/Frank Gunn