DUBLIN, IRELAND - MAY 18: Queen Elizabeth II and Prince Philip, Duke of Edinburgh arrive to attend a State Banquet in Dublin Castle on May 18, 2011 in Dublin, Ireland. The Duke and Queen's visit to Ireland is the first by a monarch since 1911. An unprecedented security operation is taking place with much of the centre of Dublin turning into a car free zone. Republican dissident groups have made it clear they are intent on disrupting proceedings. (Photo by Oli Scarff/Getty Images)
