Swansea Borough was granted its first charter by William de Newburgh, earl of Warwick, between 1158 and 1184. Up until the Reform Act of 1832 the borough lay entirely within the parish of Swansea, bounded by the River Tawe as far as the Bwrlais Brook (a little above High Street Station), along this brook to Cwmbwrla, round Townhill to Cockett, then down Brynmill Stream to the sea, and along the sea shore to the mouth of the River Tawe. This area was divided originally into two distinct areas, the Town, and the Franchise, which was the rural part of the Borough to the west of the town. By the 19th century the distinction became less pronounced and the old borough became known as 'The Town and Franchise of Swansea' as though it were a single unit.
There were three major Borough extensions, first in 1835, when Morriston, St Thomas, Landore, St John-juxta-Swansea, and part of Llansamlet parish were added, and again in 1889 when areas around Cwmbwrla and Trewyddfa were included, and in 1918 when the borough was enlarged to include the whole of the ancient parish of Swansea, the southern part of Llangyfelach parish, all of Llansamlet parish, and Oystermouth Urban District Council and Brynau parish.
The Borough received County Borough status in 1889 under the 1888 Local Government Act, and was accorded city status in 1969. Under local government reorganisation in 1974 Swansea County Borough and Gower Rural District were merged to create the new Swansea City Council, while many of the powers of the County Borough were transferred to the new county of West Glamorgan. In 1982 the city was granted a Lord Mayor.
In 1996 in Wales, district and county councils were abolished in favour of unitary authorities. The western part of West Glamorgan, consisting of the whole of Swansea City and the western half of Lliw Valley Borough Council, became the City and County of Swansea.