Reginald Hall
Admiral Sir William Reginald Hall (1870-1943) was the British Director of Naval Intelligence (DNI) from 1914 to 1919. Together with Sir Alfred Ewing he was responsible for the establishment of the Royal Navy's codebreaking operation, Room 40, which decoded the Zimmerman telegram, a major factor in the entry of the United States in World War I.
The son of Captain William Henry Hall, the first head of Naval Intelligence, Hall entered the Navy in 1884. He was promoted to Commander in 1898 and became Captain in 1905. He was an inspector of mechanical training from 1906-07; and from 1911-13 he served as Assistant Comptroller of the Royal Navy. In between he commanded the cadet training ship Cornwall, the armoured cruiser HMS Natal and the battle cruiser HMS Queen Mary in 1913-1914. He introduced many reforms, including the now standard three-watch system, in which one-third of the crew would be on shipboard duty at any one time.
Hall became DNI in October 1914 and served in that capacity until January 1919 when he retired from active duty. He was responsible for building up the naval intelligence organization during the war, encouraged codebreaking and radio-intercept efforts and provided the fleet with good intelligence. He also encouraged cooperation with other British intelligence organizations, such as MI5, MI6 and the Special Branch of Scotland Yard. He was knighted in 1918 due to work on the Zimmerman telegram. He was promoted to Rear Admiral in 1917, then to Vice Admiral in 1922 and to full Admiral in 1926.
Upon retirement Hall also served as a Conservative Member of the House of Commons representing West Derby, Liverpool. In the 1920s and 1930s he travelled extensively in the United States to give lectures on intelligence gathering matters. Too old to return to active service on the outbreak of World War II, Hall nevertheless served in the British Home Guard until his death.
Hall was described by the U.S. Ambassador to the Court of St. James Walter Hines Page as a "clear case of genius", a testament to his loyalty, skill and competence, qualities needed at a such a critical period of time.
He was known as "Blinker" on account of a chronic facial twitch, which caused one of his eyes to "flash like a Navy signal lamp".