LUXEMBOURG - MAY 11:  Catherine, Duchess of Cambridge visits the Grand Duke Jean Museum of Modern Art (MUDAM) to view exhibitions by British artists Sir Tony Cragg and Darren Almond during a one day visit on May 11, 2017 in Luxembourg. The Duchess is participating in the official commemoration of the 1867 Treaty of London and will attend a series of engagements to celebrate the cultural and historic ties between the UK and Luxembourg.  (Photo by Paul Edwards - WPA Pool/Getty Images)