Network SouthEast was created in 1982 as one of three British Rail passenger sectors. Prior to 1986 it was known as London & South Eastern. Despite its title, its territory stretched as far as Exeter in the west and to parts of East Anglia, although the Class 423 4-VEPs it inherited were restricted to South London and urban services in the densely populated south-east on account of them operating on the 750v DC third-rail network. A good number of these units were cascaded to the three privatised southern train operators and were among the last slam-door stock in operation on Britain’s railways.