Alan Turing saved millions of lives. But Bletchley Park wasn’t the only major code-breaking operation during World War II. Down under, there was Central Bureau.

Central Bureau—Australia’s own large and sophisticated intelligence network, built from scratch. It was this group of mathematicians, code-breakers, and radio experts who intercepted the travel plans of the architect of the Pearl Harbor attack, Admiral Yamamoto, leading to his ambush and death. Australian signals intelligence also played a vital role in the battles of the Coral Sea, Milne Bay, Hollandia, and many others. General Douglas MacArthur, the supreme commander of the local Allied forces, went so far as to insist that the men of Central Bureau accompany him on his counter-attack in the Pacific.

After the war, the US sought to give these non-combatants the highest awards possible—honors that were suppressed by the Australian government in their need for secrecy. A groundbreaking work of military history, The Secret Code-Breakers of Central Bureau gives these talented and dedicated individuals their due at last. It is a rich account of the shadowy side of military strength and of the men and women whose work was, in the words of the US navy, of ‘immeasurable importance in the successful prosecution’ of the Pacific War.