SOUTHERN FOOTBALL LEAGUE
Professional football (and professional sport in general) developed more slowly in Southern England than in Northern England. Professionalism was sanctioned by the The Football Association as early as 1885, but when The Football League was founded in 1888 it was based entirely in the North and Midlands with the establishment of County Football Association's in the South being firmly opposed to professionalism.
Woolwich Arsenal were the first club in London to turn professional in 1891 and were one of the prime motivators behind an attempt to set up a Southern League to mirror the existing Northern and Midlands based Football League. However, this venture failed in the face of opposition from the London Football Association and Woolwich Arsenal instead joined the Football League as its only representative south of Birmingham in 1893.
A competition for both professional and amateur Southern clubs was founded in 1894 under the initiative of Millwall Athletic (now simply Millwall). Initially only one division was envisaged, but such was the enthusiasm, that eventually two divisions were formed.
The Southern League soon became the dominant competition outside The Football League in Southern and Central England. In 1907, it accepted Bradford Park Avenue, a northern club, as a member, reflecting its senior position at the time. Of all the original founder members, six – Gillingham (as New Brompton were renamed), Luton Town, Millwall, Reading, Southampton and Swindon Town – are now Football League clubs.
Whilst still a Southern League club, Tottenham Hotspur became the first and so far only team to win the FA Cup after the establishment of the Football League in 1888-89 as a non-League club. This happened in 1901, although Southampton reached the final in 1900 and 1902 showing the strength of the Southern League.
In 1920, virtually the entire top division of the Southern League was absorbed by the Football League to become that league's new Third Division.
A year later the Third Division was expanded and regionalised. The Third Division clubs from the previous season became the Third Division South, with the addition of the Third Division North.