The Isthmian League is a regional men's football league covering London, East and South East England featuring mostly semi-professional 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 72 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 National League South.