The Royal Family Attend The European Horse Trials At Windsor Great Park :An amusing incident as Prince Charles places his gloves over his eyes, while H.M. the Queen is in conversation with H.M. the Queen Mother.H.M. the Queen, the Duke of Edinburgh, Princess Margaret and other of the Royal Family, are among the spectators watching the European Horse Trials, in which ten nations are competing These trials, which began today in Windsor Great Park, will continue until Saturday. May 17, 1955. (Photo by Fox Photos).