into hiding and went into hiding himself. On 2 June 1944, four days before the D-Day Normandy landings, at an improvised airstrip in France's Massif Central, Bertrand, his wife and a Jesuit priest who served as a courier of the Polish Resistance climbed into a small, unarmed Lysander III aircraft that flew them to southern England. Bertrand and his wife moved into a house in the Hertfordshire village of Boxmoor just a short walk from the Polish radio-intercept station and cipher office at the nearby village of Felden where Marian Rejewski and Henryk Zygalski were working. Bertrand retired from the French Secret Service in 1950 and went on to become mayor of Théoule-sur-Mer in southern France. In 1973, the Paris publishing house Plon published his book, Enigma ou la plus grande énigme de la guerre 1939-1945 (Enigma, or the Greatest Enigma of the War of 1939-1945). The book, one of the principal primary sources on the history of Enigma decryption, for the first time gave a detailed account of the some eleven years of Franco-Polish collaboration in breaking and reading Enigma before and during World War II. See also Cryptanalysis of the Enigma Wilfred Dunderdale Ultra Notes References Gustave Bertrand, Enigma ou la plus grande énigme de la guerre 1939–1945 (Enigma: the Greatest Enigma of the War of 1939–1945), Paris, Librairie Plon, 1973. Władysław Kozaczuk, Enigma: How the German Machine Cipher Was Broken, and How It Was Read by the Allies in World War Two, edited and translated by Christopher Kasparek, Frederick, MD, University Publications of America, 1984. Jacek Tebinka, "Account [by] the former Chief of Polish intelligence [dated 31 May 1974] on [the] cracking [of] the Enigma code," in Jan Stanislaw Ciechanowski, ed., Marian Rejewski 1905–1980: Living with the Enigma secret, 1st ed., Bydgoszcz City Council, 2005, , p. 210, footnote 19. 1896 births 1976 deaths French military personnel of World War I French military personnel of World War II