Queen Elizabeth II and the President of Ireland, Michael D. Higgins, arrive in a state carriage at Windsor Castle in England on April 8, 2014. This is the first official visit by the head of state of the Irish Republic to the United Kingdom. (Photo by Steve Parsons – WPA Pool/Getty Images)
Queen Elizabeth (center) shows Irish-related items from the Royal Collection to President Higgins (right); his wife, Sabina Coyne; and Prince Philip (left) in the Green Drawing Room at Windsor Castle. (Photo by Justin Tallis – WPA Pool/Getty Images)
Sabina Coyne, Michael Higgins, Queen Elizabeth and Prince Philip pose for a photograph ahead of a state banquet. (Photo by Dan Kitwood/Getty Images)