[1] Up to season 1972–73, Scotland's rugby union clubs participated in what was known as the Scottish Unofficial Championship.

Starting in season 1973–74, the Scottish Rugby Union organised the full member clubs into six leagues.

For the first time since before the First World War, the domestic game was producing an adequate number of players of genuine international class.

Heriot's FP became the first city club to win the championship, they had already attracted "outsiders"; their leading try-scorer was Bill Gammell, a Fettesian already capped for the Scotland national rugby union team while playing for Edinburgh Wanderers.

Recently, however, the Borders domination has faded and Glasgow Hawks won the title three times in successive years between 2003 and 2004 and 2005–06.

Since the advent of the leagues, the Scottish Rugby Union and its member clubs have re-organised the competition several times, usually to change the number of teams.

The Super 6 format was intended to bridge the gap between the amateur grade and the professional United Rugby Championship teams.

Currie Chieftains, Marr and a rejuvenated Hawick team became regular finishers in the playoff spots on the table from between the 2019/20 season and the present one (2023/24).