In what year was the team founded that won the 1956-1957 Irish League championship?
1956–57 Irish League The Irish League in season 1956–57 comprised 12 teams, and Glenavon won the championship.
Cabinteely F.C. Cabinteely Football Club (Irish: "Cumann Peile Cábán tSíle" ) is an association football club based in Cabinteely, County Dublin, Ireland comprising adult and a large number of youth under-age teams for both males and females, 60 teams in all. Cabinteely competed in the 2015 League of Ireland after being granted a licence by the Football Association of Ireland in January.