||This article needs additional citations for verification. (January 2011)|
Division One North
Division One South
|Number of teams||66
Premier Division: 22
Division One North: 22
Division One South: 22
|Levels on pyramid||7 and 8|
|Promotion to||Conference South|
|Relegation to||Combined Counties League
Eastern Counties League
Essex Senior League
Spartan South Midlands League
Sussex County League
|Domestic cup(s)||FA Cup
Isthmian League Cup
|Current champions||Whitehawk (Premier Division)
Grays Athletic (Division One North)
Dulwich Hamlet (Division One South)
|2012–13 Isthmian League|
The Isthmian League is a regional men's football league covering London and South East England featuring semi-professional and amateur clubs. It is sponsored by Ryman, and therefore officially known as the Ryman League. It was founded in 1905 by amateur clubs in the London area. It now consists of 66 teams in three divisions; the Premier Division above its two feeder divisions, Division One North and Division One South. Together with the Southern League and the Northern Premier League, it forms the seventh and eighth levels of the English football league system. It has various regional feeder leagues and the league as a whole is a feeder league mainly to the Conference South.
Before the Isthmian League was formed, there were no leagues in which amateur clubs could compete, only cups. Therefore a meeting took place between representatives of Casuals, Civil Service, Clapton, Ealing Association, Ilford and London Caledonians to discuss the creation of a strong amateur league. All the clubs supported the idea and the Isthmian League was born on 8 March 1905. Membership to the league was through invitation only. The league was strongly dedicated to amateurism; the champions did not even receive a trophy or medals; the league motto was honour sufficit. Teams less able to compete financially thus gravitated to it rather than the Southern League, while those with ambition and money would move in the opposite direction. Although the league established itself as one of the strongest amateur leagues in the country, routinely providing the winners of the FA Amateur Cup, it was still seen as being at a lower level than the Southern League which was the top regional semi-professional league. By 1922 the league had fourteen clubs and over the next five decades, only a few new members were admitted, mainly to fill vacancies left by clubs leaving the league. Most new Isthmian League members joined from the Athenian League, which was similarly dedicated to amateurism. The Isthmian League was most likely named after the ancient Isthmian Games, with the later Athenian League, Corinthian League and Delphian League all adding a Classical flavour to amateur football competition.
The league began to admit professionalism in the 1970s. A second division of sixteen clubs was formed in 1973 and a third division followed in 1977. The league refused to participate in the formation of the Alliance Premier League in 1979 and whilst two Isthmian clubs, Enfield and Dagenham, defected to the APL in 1981, it was not until 1985 that the Isthmian League champions were given a promotion place to the newly renamed Football Conference. The reward of promotion into the Conference means that, since 1985, no team has retained the title (as had happened on 22 occasions previously). The Athenian League disbanded in 1984 when the Isthmian League Second Division split into North and South Divisions. These were restructured again to Second and Third Divisions in 1991.
In 2002, the league was restructured again, with the First and Second Divisions merging to become Division One North and Division One South, and the Third Division being renamed as Division Two. In addition, the league's three feeder leagues—the Combined Counties League, Essex Senior League and Spartan South Midlands League—ran in parallel with Division Two, and were able to feed directly into the regional Division Ones.
In 2004, The Football Association pushed through a major restructuring of the non-league National League System, creating new regional divisions of the Football Conference. The Isthmian League was reduced back down to three divisions, and its boundaries were changed to remove the overlap with the Southern League.
In 2006, further reorganisation saw a reversion to two regional Division Ones and the disbandment of Division Two. This current plan calls for clubs based on the edges of the Isthmian League's territory to transfer to and from the Southern League as necessary to maintain numerical balance between the leagues. One team, Clapton, had been ever-present in the Isthmian League since its foundation, but they moved to the Essex Senior League for the 2006–07 season.
The Isthmian League was the first league to have sponsorship, having been selected by Rothmans, who sponsored the league from 1973 to 1977. The company offered prize money for position in the league but money was deducted for bookings. Thus the money encouraged both more goals and fair play. The sponsors after Rothmans to the present day have been: Michael Lawrie (1977–78), Berger (1978–82), Servowarm (1982–85), Vauxhall-Opel (1985–90), Vauxhall (1990–91), Diadora (1991–95), ICIS (1995–97) and Ryman (1997–present).
League Cup 
The Isthmian League Cup has run since 1975 and involves all Isthmian League teams.
Youth League 
Since 2007, the Isthmian League has run a youth league called the Isthmian Youth League. This league is not restricted to members of the Isthmian League.
For the 1973–74 season, the Second Division was added.
|Season||First Division||Second Division|
|1974–75||Wycombe Wanderers||Staines Town|
For the 1977–78 season, the Premier Division was added.
|Season||Premier Division||First Division||Second Division|
|1977–78||Enfield||Dulwich Hamlet||Epsom & Ewell|
|1978–79||Barking||Harrow Borough||Farnborough Town|
|1980–81||Slough Town||Bishop's Stortford||Feltham|
|1981–82||Leytonstone & Ilford||Wokingham Town||Worthing|
|1983–84||Harrow Borough||Windsor & Eton||Basildon United|
For the 1984–85 season, the Second Division was reorganised into North and South regions.
|Season||Premier Division||First Division||Second Division North||Second Division South|
|1984–85||Sutton United||Farnborough Town||Leyton Wingate||Grays Athletic|
|1985–86||Sutton United||St Albans City||Stevenage Borough||Southwick|
|1986–87||Wycombe Wanderers||Leytonstone/Ilford||Chesham United||Woking|
|1987–88||Yeovil Town||Marlow||Wivenhoe Town||Chalfont St Peter|
|1988–89||Leytonstone/Ilford||Staines Town||Harlow Town||Dorking|
|1989–90||Slough Town||Wivenhoe Town||Heybridge Swifts||Yeading|
|1990–91||Redbridge Forest||Chesham United||Stevenage Borough||Abingdon Town|
For the 1991–92 season, the regional Second Divisions were merged and the Third Division was added.
|Season||Premier Division||First Division||Second Division||Third Division|
|1991–92||Woking||Stevenage Borough||Purfleet||Edgware Town|
|1992–93||Chesham United||Hitchin Town||Worthing||Aldershot Town|
|1993–94||Stevenage Borough||Bishop's Stortford||Newbury Town||Bracknell Town|
|1994–95||Enfield||Boreham Wood||Thame United||Collier Row|
|1995–96||Hayes||Oxford City||Canvey Island||Horsham|
|1996–97||Yeovil Town||Chesham United||Collier Row & Romford||Wealdstone|
|1997–98||Kingstonian||Aldershot Town||Canvey Island||Hemel Hempstead Town|
|1998–99||Sutton United||Canvey Island||Bedford Town||Ford United|
|1999–2000||Dagenham & Redbridge||Croydon||Hemel Hempstead Town||East Thurrock United|
|2000–01||Farnborough Town||Boreham Wood||Tooting & Mitcham United||Arlesey Town|
|2001–02||Gravesend & Northfleet||Ford United||Lewes||Croydon Athletic|
At the end of the 1994–95 season, Enfield were denied promotion to the Conference. Their place was taken by Slough Town who finished as runners-up
For the 2002–03 season, the First Division was reorganised into North and South regions and the Third Division was disbanded.
|Season||Premier Division||Division One North||Division One South||Division Two|
|2002–03||Aldershot Town||Northwood||Carshalton Athletic||Cheshunt|
|2003–04||Canvey Island||Yeading||Lewes||Leighton Town|
For the 2004–05 season Division Ones North and South were merged.
|Season||Premier Division||Division One||Division Two|
For the 2006–07 season, Division One was reorganised into North and South regions and Division Two was disbanded.
|Season||Premier Division||Division One North||Division One South|
|2006–07||Hampton & Richmond Borough||AFC Hornchurch||Maidstone United|
|2007–08||Chelmsford City||Dartford||Dover Athletic|
|2009–10||Dartford||Lowestoft Town||Croydon Athletic|
|2010–11||Sutton United||East Thurrock United||Metropolitan Police|
|2012–13||Whitehawk||Grays Athletic||Dulwich Hamlet|
League Cup winners 
- "English Non-League Archive 1965–98". city.ac.uk. RSSSF. Retrieved 2011-05-14.
- "The Ryman Football League". isthmian.co.uk. Ryman Football League. Retrieved 3 August 2009.
- "Isthmian League History". fchd.info. Football Club History Database. Retrieved 3 August 2009.