The title Secretary General was first used in the 1920s for the head of the League of Nations. It indicated an office and supporting staff who were loyal to an international organisation, rather than to any nation. The title was resurrected for the United Nations in 1945 and subsequently at NATO. Lord Ismay, Winston Churchill’s wartime Chief of Staff, became NATO’s first Secretary General in April 1952. Ismay’s roles and responsibilities were unclear when he arrived, but when he left in 1957 the office had assumed its most important current duty of chairing the North Atlantic Council.

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