LUXEMBOURG, LUXEMBOURG - MAY 11:  Catherine, Duchess of Cambridge on a visit to the Luxembourg City Museum, where she viewed an exhibition about the city state's history and walked along the Cornicjhe, during a one day of visits in Luxembourg where she is attending commemorations marking the 150th anniversary 1867 Treaty of London, that confirmed the country's independence and neutrality on May 11, 2017 in Luxembourg, Luxembourg.  (Photo by Victoria Jones-WPA Pool/Getty Images)