Naval War College Review


Dale C. Rielage


In the almost thirty years since the public revelation that the Allies in World War II broke substantial portions of the German ENIGMA cipher system, Allied codebreaking has become a staple of our understanding of the Battle of the Atlantic. Less understood are the parallel efforts of the German navy to break Allied naval codes. The historical record of German codebreaking is comparatively fragmentary, many records having been destroyed during or imme- diately after the war. German naval intelligence was smaller than its Allied counterparts and left a smaller trace. Still, the influence of these German ef- forts on the pivotal convoy battles of the war has remained an important un- answered question.