William Reginald Hall Admiral Sir William Reginald " Blinker " Hall , KCMG , CB , RN ( 28 June 1870 – 22 October 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 Zimmermann telegram , a major factor in the entry of the United States in World War I . Royal Navy career . William Hall was born in Britford , Wiltshire , eldest son of Captain William Henry Hall , the first head of Naval Intelligence , who married the daughter of the reverend Thomas Armfield from Armley , Leeds . Hall decided on a naval career for himself when taken on a cruise on board HMS Flamingo by his father . He joined the training ship HMS Britannia in 1884 and two years later was appointed to the armoured cruiser " Northampton " . After a year he was transferred to the ironclad battleship " Bellerophon " which was part of the North American Station . In 1889 he became acting sub - lieutenant before attending courses for his Lieutenants examinations at Greenwich , the gunnery school and torpedo school where he achieved first class grades in all five of the subjects . Now as Lieutenant he was posted to the China Station where he served on the flagship , the armoured cruiser " Imperieuse " . In 1892 he was recommended to train as a gunnery officer , which involved a course in mathematics at the Royal Naval College , Greenwich , followed by a year ' s course at the gunnery school at HMS Excellent , a shore establishment at Whale Island , Portsmouth . Having qualified , he remained for a year on the staff . In 1894 Hall married Ethel de Wiveslie Abbey , daughter of Sir William . The engagement had begun when he was aged 19 , five years before , but at the time this was still considered a young age for a naval officer to get married . In 1895 he was appointed as gunnery lieutenant on the cruiser " Australia " where he served for two years before being appointed to the senior staff at Whale Island . He was promoted to Commander 1 January 1901 , in recognition of services with naval forces in South Africa , and later served on the battleship " Magnificent " , flagship of the second in command of the Channel Fleet . In 1904 he became commander of the predreadnought battleship " Cornwallis " which was commissioning with a new crew to operate in the Mediterranean . Hall had a reputation as a strict disciplinarian with an ability to get the best out of a crew , so he was given some of the worst sailors to bring up to scratch . A trick of disaffected sailors was to remove gunsights and throw them overboard , and indeed this happened . Hall instructed the master at arms to look out for two sailors who had previously been friends but who now avoided each other . He took one , told him that the other had confessed they had removed the sights , and the sailor duly confessed . Behaviour on board improved . Although Hall imposed discipline strictly , he also showed concern for the men he commanded and for their welfare , which was unusual for that time . He took particular care for the boys and junior seamen . In December 1905 he was promoted to Captain and appointed by the First Sea Lord , Sir John Fisher as Inspecting Captain of the new Mechanical Training Establishments , which Fisher had established to give engineering training to ordinary sailors ( 1906 - 7 ) . He was next appointed captain of the cadet training ship HMS Cornwall . Although not a conventional warship , this now involved Hall in intelligence work . The ship visited foreign ports , particularly in Germany which was now seen as the navy ' s greatest potential enemy , and Hall started the tour with a long list of places to investigate . In Kiel he was tasked with discovering how many slips had been constructed for building large vessels . To do this he devised a ruse with the help of the Duke of Westminster , who was visiting the port and agreed to lend his motor boat for the task . Hall and a couple of officers dressed down as sailors and took the yacht on a full speed circuit of the harbour , pretending to break down by the naval dockyard . A concealed camera was then used to take photographs of the installations . More information was discovered by careful questions ashore . In 1910 two officers , Lieutenant Brandon and Captain Trench , who had been part of Hall ' s crew gathering intelligence were sent on a ' holiday ' in Germany to collect information about coastal defences by Captain Regnart of the intelligence division . The two were captured and served two and a half years of a four - year sentence , before being pardoned in May 1913 as part of a visit by King George V to Germany . The admiralty then denied any responsibility for what had happened to the pair and their considerable financial loss as a result . When appointed director of intelligence , Hall arranged for them to be compensated . Hall was appointed to the armoured cruiser " Natal " following the death of her captain , F . C . A . Ogilvy . Ogilvy had obtained a high reputation for his ship which had beaten all records at gunnery but Hall managed to step into Ogilvy ' s place , retaining the confidence of the crew and bettering the gunnery record the following year . His reputation for unorthodox treatment of his men continued to grow , making it his business to reform recalcitrant sailors rather than simply punishing them . He had the knack of threatening men with punishments he could not deliver ( such as dismissal from the service ) if they did not reform , and succeeded . " Natal " was called upon to assist a sailing ship , the " Celtic Race " , which had lost most of her sails in a storm and was in danger of sinking . Despite the risk to his own ship , he escorted " Celtic Race " into Milford Haven . He was rewarded by the owners and underwriters , being presented with a silver table centrepiece by the Lord Mayor of Liverpool on their behalf . From 1911 - 13 he served as Assistant to the Controller of the Royal Navy . In 1913 he became captain of the battle cruiser " Queen Mary " . When he took over he was asked to take part in an experiment by the admiralty to dispense with ships police , transferring their duties to petty officers . He also introduced an innovation of his own , to divide the ships crew into three watches rather than the customary two . Hall believed that in the war with Germany which he expected , it would be impossible to run a ship continuously with just two watches . The change attracted much ridicule but when war came it was adopted on all large ships . A religious man , he arranged that a chapel was provided on board the ship , and this innovation too was adopted generally . He felt it important that the authority of petty officers should be boosted , and he did this by improving their quarters . He arranged for washing machines on board , for the convenience of the officers who no longer had to pay for laundry ashore , and to the benefit of sailors who were ' tipped ' to carry out the washing . He introduced a bookstore on board , and the navy ' s first shipboard cinema . Inadequacies in the water supply meant that it took an hour for all the stokers to finish washing after duty . Hall insisted that his engineers find a solution to provide enough hot water that they could all wash in 15 minutes , giving them more free time . These changes too became standard . Hall was criticised for being too soft with his crews , but his requirements for discipline were not relaxed . Rather , he believed that reward was necessary as well as punishment . Living conditions in society were improving generally and he believed the navy must keep pace with standards ashore . " Queen Mary " took part in the battlecruiser squadron ' s visit to Cronstadt , where the fleet officers and sailors were entertained by the Russian royal family , and a lavish ball was held on board ship as the culmination of the visit . It was the last such visit before world war I commenced and the battlecruisers transferred to their initial wartime base at Scapa Flow . Ships spent large amounts of time at sea , before the strategic situation became clearer and the fear of immediate German raids diminished . " Queen Mary " took part in the Battle of Heligoland Bight , where the battlecruisers were called upon to support a raid by destroyers and cruisers against German patrol ships operating off Heligoland . The raid was hailed as a British success , although behind the scenes it was marred by poor communications between the British forces involved . Hall ' s health had deteriorated under the stress of continuous sea service , and after three months matters had reached the point where he was obliged to request posting away from the ship . Director of the Intelligence Divisions . His seagoing career cut short by ill - health , Hall was appointed Director of the Intelligence Division ( DID ) by the Admiralty in October 1914 , replacing Captain Henry Oliver . According to Oliver , Hall ' s wife wrote to him on behalf of her husband requesting that he replace Oliver in the Intelligence Division . Hall served as DID ( the title eventually reverted to the pre - 1911 " DNI " ) until January 1919 when he retired from active duty . It turned out to be a fortunate appointment , for 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 , making the NID the pre - eminent British intelligence agency during the war . He also encouraged cooperation with other British intelligence organizations , such as MI5 ( under Vernon Kell ) , MI6 ( under Mansfield Smith - Cumming ) and the Special Branch of Scotland Yard ( under Basil Thomson ) . Ireland . Easter Rising . Thanks to intercepts from Room 40 , Hall was instrumental in the interception of the steamer " Aud " on 21 April 1916 by HMS " Bluebell " , which was carrying German arms to Ireland . The following day the man who had organised the arms shipment , Sir Roger Casement , was arrested in Tralee Bay after disembarking from a German U - Boat . Hall was aware of the upcoming Easter Rising in Dublin , but refused to reveal his sources , so that when information of the rising did reach the government , its authenticity was questioned . Hall interrogated Casement and allegedly refused Casement the opportunity of making a public demand for the cancellation of the uprising . The ' German Plot ' . When the United States broke off diplomatic relations with Germany , intercepted traffic between the US German legation and Berlin dried up as a key source of British intelligence . Less reliable information was used by intelligence chiefs including Admiral Hall , such as ' spy - obsessed loyalist residents in Ireland . ' The mass arrests of known Sinn Féin activists , following the discovery of a spurious ' German Plot ' in Ireland has been interpreted as : a striking illustration of the apparent manipulation of intelligence in order to prod the Irish authorities into more forceful action . . . when the British Government was unable to provide convincing evidence of a ' German Plot ' , nationalist Ireland concluded that it had been invented as retribution for the defeat of conscription . ' In this analysis Irish public opinion was wrong . Based on the faulty intelligence information made available to them , ' British ministers sincerely believed the threat was real ' . German counter - intelligence . Room 40 ' s decryptions also led to the capture of Captain Franz von Rintelen , a German Naval Intelligence officer who had firebombed munitions ships and factories in the neutral United States . In 1917 , Hall was awarded the Japanese Order of the Rising Sun , Gold and Silver Star , which represents the second highest of eight classes associated with the award . In that same year , he was promoted to Rear - Admiral . He was knighted in 1918 and was promoted to Vice - Admiral in 1922 and to full Admiral in 1926 , both on the retired list . Political career . Upon retirement Hall served as a Conservative Member of Parliament ( MP ) for Liverpool West Derby from 1919 to 1923 , then for Eastbourne 1925 - 29 . As an MP , in 1919 he and a group of industrialists founded a group to counter subversive actions against free enterprise known as National Propaganda , which was later renamed the Economic League ( UK ) . Even in the House of Commons he was still said to be involved in the Zinoviev letter affair in 1924 , which led to the victory of the Conservatives in the general election of that year . 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 ' s Walter Page as a " clear case of genius " , while American attaché Edward Bell described him as " a perfectly marvelous person but the coldest - hearted proposition that ever was — he ' d eat a man ' s heart and hand it back to him . " 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 " . His daughter attributed this to childhood malnutrition . ( He had attended a military boarding school in which the boys had to fill their bellies by stealing turnips from neighbouring farms . )