England Southern League Premier

Professional football (and, indeed, professional sports in general) developed more slowly in Southern England than in Northern England. Professionalism was first sanctioned by The Football Association as early as 1885, but when The Football League was founded in 1888 its member clubs were based entirely in the North and Midlands, as the county football associations in the South were firmly opposed to professionalism.

Woolwich Arsenal (nowadays simply 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. Additionally, an amateur league, the Southern Alliance, was founded in 1892, with seven clubs from the region, but that folded after one incomplete season.

Nonetheless, another attempt was made to form the Southern League, and this time it was successful. A competition for both professional and amateur 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 for the idea, that eventually two divisions were formed. The sixteen original founder members were:

2nd Scots Guards withdrew before the first season started and were replaced by Southampton St Mary's. Woolwich Arsenal attempted to add their reserve side to the second division but this application was refused due to the club's existing membership of The Football League.

The Southern League soon became the dominant competition below The Football League in Southern and Central England, and by the turn of the century a few of the Southern League sides began to seriously rival the Football League in the FA Cup. A preview of the 1900–01 season in the Daily News described the league as "now, without a doubt, second only in importance and the strength of its clubs to the Football League itself. With the exception of Woolwich Arsenal, who prefer to remain members of the Second Division of the Football League, all the best professional teams in the South are now enrolled in the ranks of the Southern League".

Two Southern League clubs, Southampton (in 1900 and 1902) and Tottenham Hotspur (in 1901) reached the final of the FA Cup around the turn of the twentieth century. Tottenham Hotspur remain the only club from outside the Football League (and since its inception, also the Premier League) to have won the FA Cup.

Several of the best players in England moved from the Football League to the Southern League around this time, due to the restrictions on their freedom of movement and wages implemented by the Football League between 1893 and 1901, and the failed efforts of the Association Footballers' Union (the AFU) to relax the restrictions. This ended in 1910 when the League came to a reciprocal agreement with the Football League.

The champions of the two leagues during this period met in the annual Charity Shield. Out of the six meetings the respective league champions had in the Shield, however, only one was won by the Southern League champions – Brighton & Hove Albion, in 1910, and this remains their only top level national honour. Up until World War I, the league also organised several representative 'inter-league' matches, against the Football League XI and the Scottish Football League XI. They won the inaugural inter-league equivalent of the British Home Championship in 1910, defeating the Football League 3–2, Scottish League 1–0 and the Irish League 4–0.

In 1907, it accepted newly converted-to-Association and future Football League club Bradford, a northern club, as a member, reflecting its senior position at the time. Stalybridge Celtic and Stoke also joined before the First World War.

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.^[]

Of the original founder members, six – Gillingham (formerly New Brompton), Luton Town, Millwall, Reading, Southampton and Swindon Town – went on to be Football League clubs.^[]

For the next six decades, the Football League and Southern League would occasionally exchange a limited number of clubs as a result of the older league's re-election process. From 1920 onward, the Southern League's status as a semi-professional league was firmly established. In 1977, Wimbledon became the last Southern League club to successfully achieve election into the Football League.^[]

With its clubs seeking a more regular means of advancing to the Football League, in 1979 the Southern League became a feeder to the new Alliance Premier League along with the Isthmian League and the Northern Premier League, and the top Southern clubs of the day joined the new league. In turn, the APL (renamed Football Conference in 1986 and National League in 2015) would eventually succeed in becoming a feeder to the Football League. The league lost more of its top clubs in 2004 when the Conference added two regional divisions below the existing National League, the Conference South and Conference North.^[]

In May 2017, the FA chose the Southern League to add an additional division at step 3 as part of another restructuring in the NLS; the two Premier Divisions were set at 22 clubs each. The new Central Division started playing in the 2018–19 season.

The first sponsor of the Southern League was Beazer Homes who sponsored the league from 1987 to 1996. The sponsors after Beazer Homes to the present day are: Dr Martens (1996–2004), British Gas (2006–2009), Zamaretto (2009–2011), Evo-Stik (2011–2013), Calor Gas (2013–2014), Evo-Stik (2014–2019) and BetVictor (2019–2020). From the 2020–21 season the league has been sponsored by Pitching In, Entain's grassroots sports investment programme. At the time of announcement, Entain went by its former name GVC Holdings. Under this partnership, the Southern League is marketed as one of the three Trident Leagues, alongside its Isthmian and Northern Premier counterparts.