Southwick House

Southwick House is a manor house of the Southwick Estate located just to the north of Portsmouth in Hampshire, England. The house was built in 1800 in the late Georgian style. The house is distinct for its two-story foyer lit from a cupola, and a series of elliptical rooms. A hemi-circular portico is centered on the house's colonnade of paired Ionic columns.

The house became important during World War II. In 1940 the estate owners allowed the Royal Navy (RN) to use the house to accommodate overnight pupils of the RN School of Navigation, HMS "Dryad" in Portsmouth Naval Dockyard. In 1941, after heavy bombing of the dockyard, the house was requisitioned and became the new home of HMS "Dryad".

In 1943, with the planning for D-Day already underway, the house was chosen to be the location of Supreme Headquarters Allied Expeditionary Force. Because of this, HMS "Dryad" was moved out of the house onto further land requisitioned from the estate.

In 1944, in the months leading up to D-Day, the house became the headquarters of the main allied commanders, including Naval Commander-in-Chief Admiral Ramsay, Allied Supreme Commander General Eisenhower and the Army Commander-in-Chief General Montgomery.

After the end of the war HMS "Dryad" remained on site, with the house becoming the wardroom. In 2004 the functions of HMS "Dryad" were transferred to HMS "Collingwood" in Fareham and the site reverted to its original name of Southwick Park. Since then it has been home to the tri-Service Defence Police College.

The large wall maps that were used in planning D-Day are still in place in the house, with the various markers showing the positions of the involved forces at the moment the first landing commenced.