The Class 465 Networker electric multiple units were built by GEC Alsthom (Metro-Cammell) and BREL between 1991 and 1993, and by ABB Rail between 1993 and 1994. They were brought into service from 1992 and operated by British Rail until 1997, then by Connex until 2003, then by South Eastern Trains until 2006 and then by Southeastern until now. The Class were introduced to replace the elderly Class 415 (4EPB) units operating on sub-urban routes around North Kent.

The Networker design was to become effectively the third generation of British Rail multiple units, and was originally intended to become one of the largest families of trains, bigger even than the largely Mark 3 based Second Generation, and was supposed to cover all the requirements for all future Network Southeast multiple units. Bombardier Transportation has used the Networker as the basis for their successful post-privatisation Turbostar and Electrostar units; having obtained the design through their acquisition of ADtranz which had absorbed ABB.