Admiral Hugh Sinclair, chief of Britain’s foreign intelligence service MI6, died on this day. He was replaced by his deputy, Stewart Menzies.
Admiral Sinclair led MI6 (SIS) during the early months of World War 2. In October 1939, he became seriously ill with cancer, leading to Permanent Under-Secretary of State for Foreign Affairs Alexander Cadogan to observe he had deteriorated since they had last met.
In 1938, the Foreign Secretary Lord Halifax, and the Prime Minister Neville Chamberlain, asked Admiral Sinclair to create an MI6 dossier on Adolf Hitler.
[Hitler possesses the characteristics of] fanaticism, mysticism, ruthlessness, cunning, vanity, moods of exaltation and depression, fits of bitter and self-righteous resentment; and what can only be termed a streak of madness; but with it all there is a great tenacity of purpose, which has often been combined with extraordinary clarity of vision.Hugh Sinclair, MI6 Chief, describing Hitler in December 1938.
The response of the British government was unease with the dossier as it contradicted their efforts to appease the Nazi government.
Sinclair was Director of British Naval Intelligence between 1919 and 1921, and he subsequently helped to set up the Secret Intelligence Service (SIS, commonly MI6) and GCHQ.