The headquarters are based on the grounds of Eastbury Park, the estate purchased by David Carnegie in 1857. During the Second World War, in 1939 the Royal Air Force took over the site for the use of RAF Coastal Command which made use of the Eastbury house and also created a network of underground bunkers and operations blocks. The house was used as an Officers' Mess though was subsequently damaged by fire.
In 1953, the NATO Commander-in-Chief Eastern Atlantic Area, who was also Commander-in-Chief Fleet, established his Headquarters at Northwood.
In April 1963 the Naval unit at Northwood was commissioned as HMS Warrior and in September 1971 the Royal Navy took over responsibility for the whole site. In 1978 the Flag Officer Submarines also moved his Headquarters to Northwood.