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History World War Ii

One Day in August

The Untold Story Behind Canada's Tragedy at Dieppe

by (author) David O'Keefe

Knopf Canada
Initial publish date
Oct 2014
World War II, Strategy, General
  • Paperback / softback

    Publish Date
    Oct 2014
    List Price

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One of the most important Canadian non-fiction books we have published: the groundbreaking, thrilling, ultra-secret story behind one of WWII's most enduring mysteries, which fundamentally changes our understanding of this sorrowful event in Canada's past.
     The Dieppe Raid--the darkest day in Canadian military history--has been one of the most perplexing mysteries of WWII, when almost 4,000 Canadian amphibious troops stormed the small French port town, only to be ambushed by the waiting Germans, slaughtered, wounded or captured. This catastrophe, coupled with the 7 decades-long mystery surrounding the reason for the operation, left a legacy of bitterness and recriminations and controversial charges ranging from incompetence to conspiracy. O'Keefe's detective-like research over 15 years in the Intelligence archives of 5 countries now reveals that it was a vitally secret "pinch raid," organized by British Naval Intelligence and the Joint Intelligence Committee. The mission: under cover of a raid to secretly steal the German code books that would unlock the Enigma cipher machine that held the key to the German High Command's plans. One of the key figures behind the mission, along with Mountbatten and Churchill, was Commander Ian Fleming, waiting in a ship off-shore for the code books that might have saved countless lives and shortened the war by some years.

About the author

David O’Keefe is an award-winning historian, documentarian and professor at Marianopolis College in Westmount, Quebec. He served with the Black Watch (Royal Highland Regiment) of Canada in the Canadian Forces in Montreal and worked as a Signals Intelligence research historian for the Directorate of History and Heritage (DND). He has also created and collaborated on over 15 documentaries for History Television and appeared on CBC Radio, Global Television and the UKTV Network in Great Britain.

He wrote and produced the groundbreaking documentary Dieppe Uncovered, which made headlines around the world, as well as the documentary Black Watch Snipers, which aired on History Television in November 2016. He is also the writer, producer and personality of the History Television program War Junk, in which he and his partner, Wayne Abbott, tour the battlefields of Europe for lost items from Canadian soldiers and reunites them with the families of the veterans. He is the author of One Day in August: The Untold Story Behind Canada’s Tragedy at Dieppe, which reveals in full, for the first time, the Ultra Secret story behind one of WWII’s most controversial mysteries—and one of Canada’s most sorrowful moments. One Day in August was a national bestseller, a Globe and Mail Best Book of the Year, and a finalist for the RBC Taylor Prize.

He is highly active in the media, is extremely well connected and is an accomplished public speaker. He attended IFOA the year he was a finalist for the Taylor Prize. O’Keefe lives and works in Montreal, Quebec, with his wife and children.


David O'Keefe's profile page


  • Short-listed, RBC Taylor Prize

Editorial Reviews

Praise for One Day in August:
 • "A fast-paced and convincing book, One Day in August . . . clears up decades of misinformation about the ignoble raid and should provide comfort for the few remaining survivors of that notorious massacre." James Macgowan, Toronto Star
 • "O'Keefe tells a masterful story of the intrigue and cryptology behind the fighting forces." The Globe and Mail

Other titles by David O'Keefe