West Anglia Great Northern

During 1995, amid the privatisation of British Rail, several individuals from the bus industry decided to found their own company, Prism Rail, to bid for some of the newly created rail franchises. In its bid for the West Anglia Great Northern franchise, Prism promised that it would make a premium payment of £24.8 million to the franchising office in 2004. During December 1996, it was announced that Prism had been awarded a seven year concession to operate the franchise, which was the company's fourth awarding of a passenger train franchise at that time.

On 5 January 1997, West Anglia Great Northern commenced operations, taking over service from British Rail, including their rolling stock. During the late 1990s, West Anglia Great Northern submitted an application to operate extended services on an open access basis between Peterborough and Doncaster; however, the proposal was rejected by the Office of Rail Regulation (ORR) due to a reported lack of capacity on the route.

By 1999, according to statistics compiled by the Office of Passenger Rail Franchising, West Anglia Great Northern was amongst the best performing franchises, being one of only seven franchises to obtain a B grade, for which its average punctuality had to be above 90 per cent while its average reliability figures had to exceed 99 per cent.

During July 2000, it was announced that Prism Rail, and thus West Anglia Great Northern as well, had been acquired by the British transport conglomerate National Express in exchange for £166 million. That same month, the company had agreed to invest £20.5m into the network, and had reported that the Great Northern portion of the franchise' operations were running at a profit.

In January 2002, as part of a wider reorganisation of the various franchises conducted by the Strategic Rail Authority (SRA), it was announced that the franchise would be divided, and that the West Anglia portion would be merged into the Greater Anglia franchise. During December 2003, the SRA awarded the Greater Anglia franchise to National Express, resulting in the transfer of the West Anglia services to One on 1 April 2004. The company was also granted a two-year extension on the West Anglia Great Northern franchise; thereafter, the Great Northern services were retained with the company commonly referring to itself as WAGN rather than West Anglia Great Northern.

On 10 May 2002, a major rail accident involving a northbound WAGN service occurred at Potters Bar, resulting the deaths of seven people and the injury of a further 76. The train, a four-coach Class 365 Electric multiple unit, had derailed while passing over a set of points just south of Potters Bar railway station at 97 mph (156 km/h); these points had unintentionally moved while still underneath the third coach. In the aftermath of the accident, WAGN services were heavily disrupted and delayed, leading to a special timetable being implemented for a time. During April 2004, the railway infrastructure services company Jarvis plc admitting liability for the accident.

West Anglia Great Northern operated all-stops and limited stops West Anglia services out of London Liverpool Street to Chingford, Enfield Town, Hertford East, Stansted Airport, and Cambridge, and all-stops and limited stops Great Northern services out of London King's Cross to Cambridge, King's Lynn and Peterborough, including the Hertford North loop line.