A ground breaking history of the 1920s Irish Republican Army (IRA) based on the authors’ cracking of the organization’s secret communications code. The result is a fascinating - and at times unsettling - account of the IRA’s best-kept secrets: the secret 1925 agreement with the Soviet Union, military espionage in America, plans for a gas attack on Dublin, attempts to provide military assistance to Chinese nationalists and much more.

Decoding the IRA provides a unique insight into what was one of the most innovative and important revolutionary organizations of the twentieth century. This book will lead to a re-evaluation of the IRA and its methods. It also reveals the IRA’s espionage for the Soviet Union, which posed a hitherto unrecognized threat to the security of the United States. The research is meticulous and the writing lucid and even handed.

Codebreaker and co-author, James Gillogly, gives a step-by step account of his strategy and techniques in breaking the IRA’s code and revealing the contents of hundreds of secret documents. Several of these are reproduced in the book, along with Gillogly’s decryptions.

The book will be of interest to both the historian and the broader public, particularly those with an interest in revolutionary organizations and the world of intelligence.

Reviews:

'Jaw-droppingly fascinating' - The Sunday Tribune (Dublin)
'Fascinating' - Books Ireland

'Absolutely engrossing' - The Cryptogram

'Gillogly’s explanations…give great insight into how codebreaking works in the real world' - The Mathematical Association of America

'A literally unique insight into the thinking and activities of the IRA of the 1920s and 1930s, warts, mustard gas and all' - Tim Pat Coogan