The 1st Durham Rifle Volunteers, later the 5th Battalion, Durham Light Infantry (5th DLI), was a part-time unit of the British Army from 1860 to the 1950s. Beginning from small independent corps of the Volunteer Force recruited in County Durham and Teesside, it became part of the Territorial Force and served as infantry in some of the bloodiest actions of the First World War. Later it was converted to anti-aircraft units that served during the Second World War both in Home Defence and in North-West Europe. Its successor units continued in the air defence role in the postwar Territorial Army until 1975.