In the first season of the English rugby union league pyramid, sponsored by Courage, there was four, tier five leagues. The geographical area for teams in South West Division One covered an area of south-west England from
Oxfordshire and
Berkshire in the east to
Cornwall in the west. There were eleven teams in the league and they played each team once, giving each team ten matches. The other tier five leagues were London 1, Midlands 1 and North 1. This system prevailed for five seasons, and in 1992–93 the number of teams increased from eleven to thirteen. The following season (1993–94) the league was reorganised and the four tier five leagues became two;
National 5 North and National 5 South. After three seasons, in 1996–97, a further reorganisation occurred, and there was a return to four, tier five leagues; with South West Division One covering the area of south-west England from Berkshire westwards. This system prevailed until 2009–10 when the number of teams was increased from twelve to fourteen and renamed National League Three South West. There was a name change for the beginning of season 2017–18 when the division was renamed the South West Premier.
South West 1 (1987–1993) The original South West 1 was a tier 5 league with promotion up to
Area League 2 South and relegation down to South West 2 (presently split into two leagues known as
South West 1 East and
South West 1 West).
South West 1 (1993–96) The top six teams from South West 1 and the top six from
London 1 were combined to create
National 5 South. South West 1 dropped to become a tier six league and was one of two feeder leagues for National 5 South. Relegation continued to South West 2 (currently
South West 1 East and
South West 1 West).
South West 1 (1996–2009) At the end of the 1995–96 season
National 5 South was discontinued and South West 1 returned to being a tier 5 league. Promotion was up to
National 4 South (now known as National League 2 South), while the splitting of South West 2 into two regional divisions, meant that relegation was now down to either
South West 2 East or
South West 2 West (currently South West 1 East / South West 1 West).
National League 3 South West (2009–2017) The division was renamed National League 3 South West following a restructuring of the national leagues which led to changes at all levels. It remained a tier 5 league with promotion up to
National League 2 South (formerly National League 3 South) and relegation to either
South West 1 East or
South West 1 West (formerly South West 2 East / South West 2 West).
South West Premier (2017–2022) For the 2017–18 season all divisions at tier 5 were renamed from National League 3 to Premier meaning that National League 3 South West became known as South West Premier. Promotion continued to
National League 2 South and relegation to either
South West 1 East or
South West 1 West.
Regional 1 South West (2022–) From 2022–23 season the number of tier 5 leagues was increased from four to six. ==Promotion play-offs==