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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
Nov 2013
World War II, Strategy, General
  • Hardback

    Publish Date
    Nov 2013
    List Price
  • Paperback / softback

    Publish Date
    Oct 2014
    List Price

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Magnificent and engrossing, One Day in August reveals in full for the first time the “Ultra Secret” story behind one of WW2’s most controversial mysteries—and one of Canada’s most sorrowful moments. 
In a narrative as powerful and moving as it is authoritative,  David O’Keefe rewrites history, connecting Canada’s tragedy at Dieppe with an extraordinary and colourful cast of characters—from the young Commander Ian Fleming, later to become the creator of the James Bond novels, and his team of crack commandos to the code-breaking scientists of Bletchley Park (the closely guarded heart of Britain’s wartime Intelligence and code-breaking work) to those responsible for the planning and conduct of the Dieppe Raid—Admiral John Godfrey, Lord Louis Mountbatten, British Prime Minister Winston Churchill and others. The astonishing story critically changes what we thought we knew.
For seven decades, the objective for the raid has been one of the most perplexing mysteries of WWII. In less than six hours on August 19, 1942, nearly one thousand Canadians—as well as British and Americans—lay dead or dying on the beaches around the French seaside town, with over two thousand other Canadians wounded or captured. These awful losses have left a legacy of bitterness, recrimination and controversy. In the absence of concrete reasons for the raid, myriad theories ranging from incompetence to conspiracy developed.
Over almost two decades of research, sifting through countless recently declassified Intelligence documents, David O’Keefe skillfully pieces together the story like a jigsaw puzzle to reveal the prime reason behind the raid: a highly secret mission designed, in one of Britain’s darkest times, to redress the balance of the war. One Day in August provides a thrilling, multi-layered story that fundamentally changes our understanding of this most tragic and pivotal chapter in Canada’s history.

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

FINALIST 2014 – Canadian Authors Association Lela Common Award for Canadian History
FINALIST 2014 – John W. Dafoe Book Prize
A Globe and Mail Best Book
“A masterpiece…. Above all it reads so well. The plot, narrative and characters make it as suspenseful as a novel.” —Dr. William J. McAndrew, Historian, Directorate of History and Heritage, Department of National Defence
“O’Keefe tells a masterful story of the intrigue and cryptology behind the fighting forces…. Any subsequent book on Dieppe or Ultra intelligence will have to take into account his stunning new research and bold claims.” —Tim Cook, The Globe and Mail
“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…. O’Keefe is a meticulous writer, and he answers these questions with authority and vigour…. O’Keefe conveys the enormity of the defeat with skill and precision…. Building on the work of previous historians who didn’t have access to the documents he had, O’Keefe has provided meaning to what has always been seen as a senseless massacre.” —James Macgowan, Toronto Star  
One Day in August is an account of the Allies’ tragic raid at Dieppe with a twist—it introduces new evidence that claims to solve an important World War II mystery and put to rest a legacy of unease and confusion…. A tremendous addition to the legacy of World War II history…. For all lovers of history, cryptography, warfare, intelligence, or even conspiracy theories, O’Keefe’s work definitely deserves a read.” —The McGill Tribune
“This book is the way history should be written. It just blew me away…. When I find something that really captures… the essence of historical research, it just knocks me down….  It reads like a wartime detective story.” —Richard King, Books Columnist for CBC Radio Montreal Homerun (interview)

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