The League of Ireland is the top professional football league in the Republic of Ireland. Established in 1921, it features clubs from across the country competing for the championship title. The league operates on a promotion and relegation system with the League of Ireland First Division, which is the second tier of Irish football. The league consists of several teams, including well-known clubs like Shamrock Rovers and Cork City. Matches are typically played from February to November, with each team facing others multiple times throughout the season. The league is governed by the Football Association of Ireland (FAI).