The League of Ireland Premier Division, also known as the SSE Airtricity League Premier Division. It is the top-level division in both the League of Ireland and the Republic of Ireland football league system. The division was formed in 1985 following a reorganization of the League of Ireland. St. Patrick’s Athletic and Bohemians are the only current League of Ireland clubs never to have been relegated from the Premier Division. Since 2003 the Premier Division has operated as a summer league.
The inaugural members of the Premier Division included the League of Ireland’s traditional top four clubs – Shamrock Rovers, Shelbourne, Bohemians, and Dundalk plus eight other clubs. Shamrock Rovers were the inaugural champions and then retained the title in 1986–87. This saw Rovers complete a four in a row of league titles. Dundalk were champions in 1987–88 and Derry City achieved a treble in 1988–89 by also winning the League of Ireland Cup and the FAI Cup