During the Middle Ages the county was an ecclesiastical centre; this was mainly due to the shrine of St Cuthbert being in Durham Cathedral, and the extensive powers granted to the Bishop of Durham as ruler of the County Palatine of Durham. The county has a mixture of mining and farming heritage, as well as a heavy railway industry, particularly in the southeast of the county in Darlington, Shildon and Stockton. There was a lot of mining. It is an area of regeneration and promoted as a tourist destination; in the centre of the city of Durham, Durham Castle and Durham Cathedral are a UNESCO-designated World Heritage Site.
Many counties are named after their principal town, and the expected form here would be Durhamshire, but this form has never been in common use. The ceremonial county is officially named Durham, but the county has long been commonly known as County Durham and is the only English county name prefixed with "County" in common usage (the practice is common in Ireland). Its unusual naming (for an English shire) is explained to some extent by the relationship with the Bishops of Durham, who for centuries governed Durham as a county palatine (the County Palatine of Durham), outside the usual structure of county administration in England. The signage as you enter County Durham reads - "Welcome to County Durham Land of the Prince Bishops". "County Durham" originated as a shortened form of "County of Durham".
The situation regarding the formal name in modern local government is less clear. The structural change legislation which in 2009 created the present unitary council (that covers a large part – but not all – of the ceremonial county) refers to "the county of County Durham" and names the new unitary district "County Durham" too. However, a later amendment to that legislation, refers to the "county of Durham" and the amendment allows for the unitary council to name itself "The Durham Council". In the event the council retained the name of Durham County Council. With either option, the name does not include County Durham.