Northumberland role in the Industrial Revolution from the 18th century on. Many coal mines operated in Northumberland until the widespread closures in the 1970s and 1980s. Collieries operated at Ashington, Bedlington, Blyth, Choppington, Netherton, Ellington and Pegswood. The region's coalfields fuelled industrial expansion in other areas of Britain, and the need to transport the coal from the collieries to the Tyne led to the development of the first railways. Shipbuilding and armaments manufacture were other important industries before the deindustrialisation of the 1980s. Northumberland remains largely rural, and is the least-densely populated county in England. In recent years the county has
Historical development of Church of England dioceses the kingdom of England in the 11th century is estimated at between one and two million, with Lincolnshire, East Anglia, and East Kent the most densely populated areas. Population density in these areas was greater than in other areas of the country where many villages had been razed by the conquest armies. Instead of exercising jurisdiction over definite areas, many of the bishops were bishops of tribes or peoples, as the bishops of the South Saxons, the West Saxons, the Somersætas, etc. The "cathedra" of such a bishop was often migratory. In 1075 a council was held in London, under