Teesside the four independent unitary authority boroughs of Hartlepool, Stockton, Middlesbrough and Redcar and Cleveland (a renamed Langbaurgh). At this time they were returned to the counties of North Yorkshire and County Durham for ceremonial purposes, with Stockton-on-Tees becoming the only district in England split between two ceremonial counties. In 1998 the neighbouring Borough of Darlington also became an independent unitary authority and this along with the four former Cleveland boroughs form the sub-region of the Tees Valley which is used for statistical purposes and governmental organisation. The name Tees Valley is increasingly promoted for economic and cultural connections, though Teesside,
County Borough of Teesside of the proposed county of Cleveland were considerably altered, with a number of marginal areas removed. Under the revised scheme, the Teesside district would have 70 percent of the county's population, and it was felt that it would dominate the county. Accordingly, new guidelines were issued to the Local Boundaries Commission in March 1972 that was charged with drawing up district boundaries: Cleveland ""should be divided into not less than four new districts with populations comparable as is reasonably practicable having regard in particular to the pattern of local government before the establishment of the Teesside county borough"". The county