This study contends that the Royal Australian Navy (RAN) did not always give sufficient consideration to the provision of intelligence support in planning and conducting combat operations in the conflicts beginning with World War II (WWII) and ending with the Vietnam War. It reconstructs the intelligence background to RAN operational activities in prosecuting the conflicts, and the specific intelligence used by operational commanders to plan and execute their missions. The study briefly describes the development of the RAN and its status at the beginning of WWII, and explains the naval, joint and Allied intelligence arrangements that paralleled the growth of the navy from a colonial squadron of the British Imperial Navy to an independent entity. It also considers the political and strategic decisions that gave the RAN its role and shaped its force structure, and the intelligence assessments that underlay them, and outlines changes in modes of warfare and the influence of technology on operations.” pp. 372 illusts maps #0717