 During the 1947 royal tour of South Africa , Elizabeth 's serene public behaviour was broken , exceptionally , when she rose from the royal car to strike an admirer with her umbrella because she had mistaken his enthusiasm for hostility . The 1948 royal tour of Australia and New Zealand was postponed because of the King 's declining health . In March 1949 , he had a successful operation to improve the circulation in his right leg . In summer 1951 , Queen Elizabeth and her daughters fulfilled the King 's public engagements in his place . In September , he was diagnosed with lung cancer . After a lung resection , he appeared to recover , but the delayed trip to Australia and New Zealand was altered so that Princess Elizabeth and her husband , the Duke of Edinburgh , went in the King and Queen 's place , in January 1952 . The King died while Princess Elizabeth and the Duke were in Kenya en route to the southern hemisphere , and they returned immediately to London as the new Queen and consort . They would not finally visit Australia and New Zealand until 1954 . 
