During the later stages of the Second World War, the bailey was levelled and used to hold a set of temporary Nissen huts that formed a hospital for United States Army personnel. In 1945, the site was leased by the Air Ministry for use as offices. The Ministry of Works took over the guardianship of the castle in 1951. The ministry put pressure on the Air Ministry to leave the site, which occurred in 1956; the bailey was then grassed over again. Archaeological excavations were carried out in the bailey between 1961 and 1982, uncovering many of the medieval buildings.