On 14 December 2009, Southeastern launched full operations of its high-speed services using a purpose-built fleet of British Rail Class 395 high speed trains.

Southeastern operated numerous commuter services that served South-East and South London as well as Kent, many of which came under the Metro brand.

It was owned by Govia, a joint venture between Go-Ahead Group and Keolis, which also operates the neighbouring Southern franchise that overlapped with Southeastern in some western areas.

[3] In November 2005, the Department for Transport (DfT) announced Govia had been awarded the franchise; the services operated by South Eastern Trains were transferred to Southeastern on 1 April 2006.

[4][5][6] During November 2007, the second phase of High Speed 1 was opened to traffic, resulting in the freeing up of train paths on the traditional network previously used by Eurostar, which permitted Southeastern to increase certain services two months later.

[8] On 14 December 2009, Southeastern launched full operations of its high-speed services using its newly procured fleet of British Rail Class 395 high speed trains.

[21] Amidst the 2016–18 United Kingdom rail strikes that impacted numerous train operators across the nation, Southeastern cleaning staff, outsourced to employment agency Wettons, voted to stage industrial action in a dispute over pay and working conditions in September 2017.

[22][23] A strike, which involved Wettons cleaning staff affiliated with the National Union of Rail, Maritime and Transport Workers (RMT), took place on 19 October 2017 and lasted for 24 hours.

[26][27] However, in December 2016, Transport Secretary Chris Grayling rejected this proposed reorganisation; the decision was quickly condemned by Mayor of London Sadiq Khan.

[28][29] In June 2017, the DfT announced that four parties, comprising an Abellio/East Japan Railway Company/Mitsui consortium, incumbent Govia, Stagecoach and Trenitalia, had been shortlisted to bid for the next South Eastern franchise.

[40][41] During September 2021, the DfT announced it would be terminating Govia's South Eastern franchise after revenue declaration discrepancies involving £25 million of public money were discovered.

[43] During December 2021, Go-Ahead issued an admission of "serious errors and failures", while the trading of its shares on the London Stock Exchange was suspended as the company was unable to publish financial results.

[45] In February 2022, Go-Ahead announced the outcome of investigations into the termination of the franchise; it found that "serious errors had been made” since 2006, with the expected cost to the company to be over £80 million.

[citation needed] When bidding for the franchise, Southeastern made a point of advertising part-owner SNCF's experience operating integrated high-speed train services on the French TGV network.

The services were marketed as Southeastern Highspeed, and some of the trains were named after British Olympians such as Steve Redgrave and Ben Ainslie.

With the fast trains now travelling over High Speed 1, the Charing Cross to Ashford stopping service was extended to Dover, Canterbury and Ramsgate.

[64] Eight trains per hour ran between St Pancras and Ebbsfleet, calling at Stratford, replacing the usual East Kent highspeed service.

'Mainline' services connect central London with Dover, Folkestone, Hastings, Royal Tunbridge Wells, Ramsgate, Chatham, Maidstone and Canterbury.

'Metro' trains served Greenwich, New Cross, Lewisham, Dartford, Gravesend, Woolwich Arsenal, Hayes, Peckham Rye, Bromley South, Bickley, Bexleyheath, Petts Wood, Orpington and Sevenoaks.

Southeastern claimed that the reason for this is that people dislike going to work and that if the survey were to be retaken on a "sunny summer's day" the outcome would be better for the company.

[73] The company issued a joint response with Network Rail on the day of publication, primarily blaming outside factors and survey methodology.

figures were backed up by the 2016 Transport Focus survey, which placed Southeastern joint bottom in satisfaction on service delivery.

The transfer of some routes to Southern and Thameslink allowed Southeastern to withdraw its small fleet of Class 508 EMUs and replace them with Networker stock cascaded from other services.