 Shortly after the outbreak of the Second World War, concerns grew in the British government about the threat of German invasion along the east coast of England.The bays just to the north of Dunstanburgh Castle were vulnerable targets for an enemy amphibious landing, and efforts were made to fortify the castle and the surrounding area in 1940, as part of a wider line of defences erected by Sir Edmund Ironside.The castle itself was occupied by a unit of the Royal Armoured Corps, who served as observers; the soldiers appear to have relied on the stone walls for protection rather than trenches, and, unusually, no additional firing points were cut out of the stonework, as typically happened elsewhere.