On 13 October 1996 Connex commenced operating the South Eastern franchise having beaten bids from a Management/FirstBus consortium, GB Railways and Stagecoach.

[2][3][4] In December 2002, after the franchise ran into financial trouble, the Strategic Rail Authority agreed to bail it out with a £58 million injection, with the end date brought forward from 2011 until 2006.

[5] However continuing poor financial management resulted in the Strategic Rail Authority deciding to strip Connex of the franchise in June 2003.

Connex South Eastern inherited a large fleet of slam-door and power-door electric multiple units from Network SouthEast.

[20] Connex South Eastern's fleet was maintained at Ashford, Ramsgate, Slade Green and Gillingham depots.