Arthur Tange joined the Commonwealth Public Service in 1942, at a point in time when it was undergoing ‘a permanent revolution at once in the size, the calibre, the philosophy and the significance’ of what it was and what it did. Most Australians now forget, if they ever knew, just how limited the function and reach of federal government was in the first decades of the Commonwealth. As in so many areas of national life, World War II wrought a profound transformation in virtually all aspects of central government and public administration, and the young Tange was in at the beginning of the process. As Sir Arthur Tange, Secretary of External/Foreign Affairs and Defence successively from the 1950s to the late 1970s, he did more in turn to shape the formulation and execution of policy in these two areas than any other official, and many ministers, of his time.