Stokes Bay has long been recognised as a strategically-important position in the outer defences of Portsmouth Harbour and has seen an unusually wide range of defensive building, spanning the period from the Spanish Armada 1588 to the Second World War 1939-45. The defence of Stokes Bay was perceived to be vital to national security, so its redoubts, batteries and forts reflect four centuries of military planning. By the mid-20th century, the factors that had previously made the bay vulnerable to invasion also made it eminently suitable as an embarkation site for raids into occupied Europe, and the earlier defences were reused and extended in the large-scale preparations for D-Day in June 1944. In the late 20th century some of the defensive sites gradually disappeared while others were retained as prominent landscape features, but the area’s military history continued to influence both residential development and its transformation into a seaside resort for visitors and tourists.