British Railways (Southern Region)

The Southern Region (SR) of British Railways was a territorial Region from 1 January 1948 until 1992. It directly inherited the Southern Railway's territory, the south-east of England south of the Thames, the Kent coast and the lines to Portsmouth, Bournemouth and Plymouth via the Withered Arm.

The Region maintained the SR's strong third-rail dc electrification tradition, extending it east through Kent (1959–1962, the Kent Coast electrification) and west to Bournemouth and Weymouth (1967 and 1988 respectively). Notable Region traction projects included the Class 71, Class 73 and Class 74 electric and electro-diesel locomotives, the 4REP and 4VEP suburban EMUs, and (later) the Class 442 'Wessex Electric' of 1988 for the Bournemouth and Weymouth expresses.

The Region's territory was sectorised into Network SouthEast for suburban work and Regional Railways for the Withered Arm during the 1980s. The Region was formally abolished in 1992.