Input (grade 12): The district was formed on 1 April 1974 by the merger of the municipal borough of Durham and Framwelgate with Brandon and Byshottles urban district and Durham Rural District.
Output (grade 11): The district was formed on 1 April 1974 when the borough of Durham and Framwelgate was joined to the, Brandon and Byshottles urban district and Durham Rural District.