Andrew Boyd - British Naval Intelligence through the Twentieth Century

BRITISH NAVAL INTELLIGENCE

To all who contributed to British naval intelligence through the twentieth century

Not by rambling operations, or naval duels, are wars decided, but by force massed and handled in skilful combination.

A T Mahan, Sea Power in its Relations to the War of 1812

ANDREW BOYD

FOREWORD BY ANDREW LAMBERT

Copyright Andrew Boyd 2020

First published in Great Britain in 2020 by

Seaforth Publishing,

A division of Pen & Sword Books Ltd, 47 Church Street,

Barnsley S70 2AS

www.seaforthpublishing.com

British Library Cataloguing in Publication Data

A catalogue record for this book is available from the British Library

ISBN 978 1 5267 3659 8 (HARDBACK)

ISBN 978 1 5267 3660 4 (EPUB)

ISBN 978 1 5267 3661 1 (KINDLE)

All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without prior permission in writing of both the copyright owner and the above publisher.

The right of Andrew Boyd to be identified as the author of this work has been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.

Pen & Sword Books Limited incorporates the imprints of Atlas, Archaeology, Aviation, Discovery, Family History, Fiction, History, Maritime, Military, Military Classics, Politics, Select, Transport, True Crime, Air World, Frontline Publishing, Leo Cooper, Remember When, Seaforth Publishing, The Praetorian Press, Wharncliffe Local History, Wharncliffe Transport, Wharncliffe True Crime and White Owl

Maps by Peter Wilkinson, diagrams by Stephen Dent Typeset by Mac Style

1 Jutland movements of the British and German fleets during the night of 31 May/1 June 1916

2 Admiralty diagram of the OIC during the Munich crisis of October 1938

3 Naval Intelligence Division in 1943

4 Soviet maritime defence zones from the early 1980s

The plate sections are between pages 296297 and 552553.

Admiral of the Fleet Sir John Fisher in 1915

Captain Sir Mansfield Cumming, first Chief of the Secret Intelligence Service

The secret agent Hector Bywater in 1909

Captain William Reginald Hall in 1914, before becoming Director of Naval Intelligence

Sir Alfred Ewing, head of Room 40, in 1915

Thringen firing on Black Prince Jutland night action

A E W Mason in 1915, Halls most important agent

Nigel de Grey, Room 40 cryptographer

Sir William Wiseman, Secret Intelligence Service representative in America, 19151918

Alastair Denniston, Head of the Government Code and Cipher School, in 1939

Alfred Dillwyn Dilly Knox, leader of the British Enigma attack in the late 1930s

The Secret Intelligence Service agent TR16s report on the Battle of Jutland Rear Admiral Sir Hugh Sinclair, Chief of the Secret Intelligence Service, 19231939

Vice Admiral Sir William James, Deputy Chief of Naval Staff, in 1936

Vice Admiral John Godfrey, Director of Naval Intelligence, in 1942

Sidney Cotton, architect of British aerial photographic reconnaissance in the Second World War

Commander Ian Fleming, staff officer to Director of Naval Intelligence

Frank Birch, head of Bletchleys naval section from 1939

Mavis Lever, who made a crucial break into Italian naval Enigma

Hugh Foss, architect of successive attacks on Japanese naval attach systems

John Tiltman, a dominant figure in British-American SIGINT for sixty years

Room 39 wartime morning meeting

Commander Rodger Winn, head of the Admiralty submarine tracking room, 19411945

Captain Alan Hillgarth as naval attach in Madrid

Aerial photograph of the German battlecruiser Scharnhorst at Kiel, June 1942

Sinking of Scharnhorst , 26 December 1943

Rear Admiral Edmund Rushbrooke, Director of Naval Intelligence, 19421946