Durham County Council is a local authority administering all significant local government functions in the unitary authority area of County Durham in North East England. The council area covers part of the ceremonial county of County Durham, excluding those parts which now form part of the Borough of Darlington, Borough of Hartlepool and the part of Borough of Stockton-on-Tees north of the River Tees. Between its establishment in 1889 and major local government reforms in England in 1974, the council administered the historic county of Durham