Reviews of Colossus: Bletchley Park’s Greatest Secret

‘Masterly in breadth and sweep ... Gannon’s account of wartime interception and decryption is deeply researched ... I commend the book to both the professional and the general reader’ - Donald Michie (former Bletchley Park codebreaker and user of Colossus), Spectator

‘A really remarkable contribution to the historiography of Bletchley, comprehensible even to an innumerate such as myself.  I thought I knew quite a bit about the war, but this book filled some yawning chasms of ignorance in my education about codebreaking’, Sir Max Hastings, author of The Secret War 1939-45

‘This book seeks to restore Colossus to its rightful place in the history of computing ... read Gannon to feel the collective power of human minds harnessed to the cause of defending our freedom’ - Georgina Ferry, Guardian

‘The pre-eminent account’ - Professor Richard J Aldrich, GCHQ: The Uncensored Story of Britain’s Most Secret Intelligence Agency

‘The first book to set the story of Colossus, the first electronic computer, in its historical context. This important account of the role Colossus played in the war effort is fascinating reading. Authoritative.’ - Rachel Burnett, IT Now (British Computer Society magazine)

‘The whole story masterfully told in Paul Gannon’s
Colossus’ - Professor Kenny Paterson

‘Paul Gannon has revealed a previously untold story ... Colossus tells of the heroic efforts of the inventors and mathematicians [who] received no recognition for decades ... Gannon sets the record straight’ - Simon Singh, Times

‘Gannon’s book is a labour of love and his knowledge is profound’ -
Will Cohu, Daily Telegraph

‘Gannon’s book contains a mass of utterly fascinating and largely unknown material about an immensely important wartime project and is very welcome indeed’ -
Brian Randell, Times Higher Educational Supplement

‘A fascinating tour through the history of Colossus for the general as well as the technical reader ... a succinct overview of codes and ciphers in modern warfare’ -
Andrew Dogshorn, Tribune

‘Gannon makes commendable efforts to explain the intricacies of codebreaking and to those with an interest in mathematics, there is a large amount of rewarding detail. For the general reader, the explanation of the wider picture is a fascinating insight into a neglected area’ -
Eibhir Mulqueen, Sunday Business Post

‘A fascinating and exhaustive history’, James Pressley, Bloomberg News

A comprehensive treatment of an important and, heretofore, not well-understood subject. A readable, thoroughly documented, valuable contribution’, Hayden Peake, Studies in Intelligence