LONDON, ENGLAND - APRIL 25:  The Dean of Westminster Dr John Hall, (2nd R) greets Queen Elizabeth II and Prince Phillip, Duke Of Edinburgh as they arriive for a Service of Commemoration at Westminster Abbey to mark the centenary of the Gallipoli and Anzac campaigns at Westminster Abbey on April 25, 2015 in London, England. (Photo by Hannah McKay-WPA Pool/Getty Images)