The Hero I-League, originally called as National Football League, is one of the two premier football leagues in the country, the other being the Indian Super League (ISL). Contested by 10 clubs (currently), it operates on a system of promotion and relegation with the I-League 2nd Division as well as a system of direct-entry.
The I-League is regarded internationally as the primary competition in Indian football. Since inception, five clubs have been crowned champions of the I-League, including Aizawl FC (once), Mohun Bagan AC (once), Bengaluru FC (twice), Churchill Brothers (twice), Dempo (thrice), Minerva Punjab FC (once) and Salgaocar (once).
Clubs from the I-League primarily participate internationally in the AFC Cup. From 2007 to 2011, the I-League champions of the previous season were allowed to play in a qualifier for the Champions League. However, to this day, no I-League club has actually qualified for the AFC Champions League.