Regional hospital boards were established in 1947 by the National Health Service Act 1946 to administer hospital and specialist services of the National Health Service in England and Wales. Each board was responsible for a number of hospital management committees. The National Health Service Reorganisation Act 1973 replaced the hospital boards with regional health authorities in 1974. Each board administered a regional hospital area, which was defined in terms of local government units: administrative counties, county boroughs, metropolitan boroughs, urban districts and rural districts.