Borough of Stockton-on-Tees: History
=== Municipal authority ===
Stockton previously held borough status as the Municipal Borough of Stockton-on-Tees in historic County Durham.
In 1968, the borough was merged into Teesside County Borough; this civil parish was a part of the ceremonial (not administrative) North Riding county until its abolition.
The town regained borough status on 1 April 1974 as a result of the Local Government Act 1972. It became a non-metropolitan district of the County of Cleveland, itself established at the same time. Multiple parishes and boroughs merged into Stockton's newly formed district borough:
Teesside County Borough's area covering the former Stockton, Billingham and Thornaby municipal boroughs,
Hilton, Ingleby Barwick, Kirklevington, Maltby, and Yarm parishes of the previous North Riding County-administered Stokesley Rural District, and
Part of the County Durham-administered Stockton Rural District parishes.
The borough became a unitary authority on 1 April 1996. It is ceremonially split between County Durham and North Yorkshire, to the north and south of the Tees respectively. It is the only council in England to be split between two ceremonial counties. The former districts and boroughs of Durham now form the unitary authority of County Durham, so ceremonial County Durham now has four unitary authorities.