Wikipedia - K League 1

The K League 1 (Korean: K리그1) is the top flight of men's professional football in the South Korean football league system. The league is contested by twelve clubs.

History

The South Korean professional football league was founded in 1983 as the Korean Super League, with five member clubs. The initial five clubs were Hallelujah FC, Yukong Elephants, Pohang Steelworks, Daewoo Royals, Kookmin Bank. Hallelujah FC won the inaugural title, finishing one point ahead of Daewoo Royals to lift the trophy.

The Super League was renamed the Korean Professional Football League, and introduced the home and away system in 1987. It was once again renamed the K League in 1998. After the 2011 season, the K League Championship and the Korean League Cup were abolished, and the league was split into two divisions in 2013. The first division was named the K League Classic, while the newly created second division was named the K League Challenge, and both are now part of the K League structure. Since its creation, the league has expanded from an initial 5 to 22 clubs. Of the five inaugural clubs, only Yukong, Pohang and Daewoo still compete in the K League; Kookmin Bank dropped out of the league at the end of 1984, and Hallelujah followed the season after.

On 22 January 2018, the top-flight competition was renamed as K League 1.