The Central Electricity Generating Board (CEGB) was the cornerstone of the British electricity industry for almost forty years, from 1957 to privatisation in the 1990s.Because of its origins in the immediate post-war period, when electricity demand grew rapidly but plant and fuel availability was often unreliable, most of the industry saw its mission as to provide an adequate and secure electricity supply, or "to keep the lights on" as they put it, rather than pursuing the cheapest generation route.It was created in 1957 from the Central Electricity Authority, which had replaced the British Electricity Authority.