The secrets of Room 40
‘Blinker’ Hall, Spymaster, by David Ramsay The first world war admiral, ‘Blinker’ Hall — so-called for the obvious reason — is less widely known than Jellicoe, Beatty & Co., but his contribution to victory and history was arguably greater. He was the Director of Naval Intelligence (DNI) who ensured the success of Room 40, the 1914 equivalent of Bletchley Park in 1939. Less famous than its successor, partly because radio was less used then, its ability to decrypt German naval and diplomatic ciphers was no less significant. Not the least of its achievements, enhanced by Hall’s outstanding political skill, was the decoding of the Zimmerman telegram, which effectively brought America