The battery was built in 1898-1900 as a combined battery to guard the eastern side of the harbour, complimenting the battery on the Citadel (TR 34 SW 222). Originally the battery had 2x9.2" BL (breech loaders) guns which were removed in 1912. By 1915 it had in position 3x9.2" Mk X's guns for Counter Bombardment 2x6" guns for Close Defence and two machine guns. In the 1920s the 9.2" guns were removed and sent to the Far East. Langdon was used as a practice battery. In 1941 the war manning of the battery was 5 officers and 110 men. Langdon Battery was placed in Care & Maintenance of three gunners in March 1945 when the tank obstacles and barbed wire were removed, and in May the following year it was handed over to the Royal Engineers. Viewed in 1980 the site was derelict and guarded by two concrete pillboxes. It was subsequently converted to the Coastguard Station in 1974. The Coastguard Station was superimposed on the site of the 9.2" emplacements. Originally the site was protected by a shallow ditch with (TR 34 SW 543) 6ft steel fence and barbed-wire entanlement, an outer fence of 4ft 6" and a musketry parapet. Later two concrete pillboxes were added to guard each entrance to the site. A caretakers cottage and officers accommodation (TR 34 SW 564) was located approximately 190m to the west of the battery. Summary from record TR 34 SW 819: A coast battery built in 1901 as part of the defences of Dover Harbour. Five emplacements for three 9.2 inch guns and two 6 inch guns.