LONDON, UNITED KINGDOM - JULY 19: (EMBARGOED FOR PUBLICATION IN UK NEWSPAPERS UNTIL 48 HOURS AFTER CREATE DATE AND TIME) David Johnston, Governor General of Canada, holds Queen Elizabeth II's arm as she departs Canada House after attending a celebration to mark Canada's 150th anniversary of Confederation on July 19, 2017 in London, England. (Photo by Max Mumby/Indigo/Getty Images)