I-League is described as the topmost level union in the Indian football league structure. In the year 2007-2008, the All India Football Federation (AIFF) started the I-League. The National Football League (NFL) that lasted for around 11 long seasons was replaced by the I-League.

History of I-League
The National Football League (NFL) had started in India as a domestic league, in the year 1996. This league was started as an effort to bring more professionalism into Indian football but this was never achieved. Few reasons include poor infrastructure of the fields playing then and the recklessness of the different clubs playing in the tournament. Ten years after the National Football League had started the AIFF had decided that they need to change the tournament into something big which would draw more crowd and bring more professionalism into football.

In the 2006-07 NFL season, the AIFF had announced that from 2007-08 season onwards, NFL would be known as I-League. The first season of I-League had seen ten teams playing. Eight teams were the ones playing in NFL previously. But two other teams were the ones which belonged to the second division league.

Early Seasons of I-League
Dempo played against Salgaocar in the very first match of the very first season of I-League. The match saw Dempo winning by 3-0. Chidi from Dempo scored the first goal when the game was on after three minutes. Thus, Chidi became the first player to score a goal in the history of I-League. That season saw Dempo winning the first ever I-League title.

In the next season, the I-League was expanded from 10 to 12 teams. Mumbai, Chirag United, Mohammedan, and Vasco were all promoted from the I-League 2nd Division to make the expansion possible. In the second season it was Churchill Brothers who came out on top beating the best teams in India then.

Format of I-League
There have been many changes yearly in the I-League with the increase in the number of teams playing every season. In I-League, each team plays an opponent twice- once home and once away. By winning a match, a team gets three points. If the match ends in a draw, both teams share one point each. By the end of the season, the team with most points wins the league.

There are some added incentives for the clubs that are taking part in the I-League. Like for instance, for promoting higher attendances as well as for improving the revenues of all the participating clubs ninety per cent of the total gate collection will be given to the host club after the deduction of the stadium hiring charges. The club will be given the charge for selling of the tickets. Moreover, the league will provide funding of around three lakh for fielding a team in the Under 19 I-League. It will also provide a financial assistance of almost three lakh for the appointment of the administrative staffs. Further, the participating clubs will be provided two edge boards, six boards and six boundary marker level boards at the first row level in the domestic games. The prize money declared for the winners has been tremendously increased. Moreover, the Runners-up of the match would receive Rs.2.8 Million (this amount increases every year).

Sponsorship of I-League
Since its advent, I-League had several different sponsors for its seasons. ONGC was the main sponsor of I-League till 2011. After that the deal with ONGC was cancelled, I-League had no sponsor till the 2013 season. However, Airtel signed a deal with AIFF and sponsored the club for a single season. From the year 2014, Hero Motocorp has been the sponsor of I-League, till the present day.

Problems of I-League
The financial instability has been the major setback for I-League. Since the league began in 2007 the league has seen four clubs disband their operations - Chirag United Kerala, JCT, Mahindra United, and Pailan Arrows. The majority of clubs in the league rely on main sponsors for fund of the team through a season at least. This is mainly due to the fact that clubs in the I-League do not rely on income from merchandise sales or ticket sales and that television revenue goes directly to the All India Football Federation instead of the clubs.

Few former international players like Renedy Singh commented that if ISL merges with the I-League the I-League would benefited. It has been seen that there is a marked decrease in the crowd coming to the stadium to watch a game. Meanwhile, the ISL manages to pull a lot of attention from the people and attract more crowd. Part of the reason for these attendances other than the lack of marketing has been cited as being the fact that most I-League matches start in the afternoon when it is way too hot for fans than during the night.

Clubs Participating in I-League
In the current season (2015-16), the following nine teams will be playing the I-League:


•Aizwal
•Bangaluru FC
•DSK Shivajians
•East Bengal
•Mohun Bagan
•Mumbai FC
•Salgaocar
•Shillong Lajong
•Sporting club de Goa

In the very first season of the I-League, the teams who played in the I-League were:-


•Air India
•Churchill Brothers FC
•Dempo SC
•East Bengal
•JCT FC
•Mahindra United
•Mohun Bagan
•Salgaocar SC
•Sporting Club de Goa
•Viva Kerela

I-League Golden Boot Winners
Odafe Onyeka Okolie and Ranti Martins are both currently the holders of the most golden boot titles with three each. The two Nigerians make up the seven golden boots won by Nigerians, the most of any nationality in the league. Odafe had been the top scorer for the first three seasons. He was playing for the Churchill Brothers then. Ranti Martins had been the top scorer two times for Dempo and one time each for Prayag United and East Bengal. In the 2013-14season, winners of the golden boot were Sunil Chhetri, Darryl Duffy, and Cornell Glenn. They had scored 14 goals each.

Trophy of I-League
I-League has only been awarding a proper trophy to the champions since 2013 when the 2012-13 season champions, Churchill Brothers, won the league. Till the year 2013 the champions of I-League received a basic trophy. The new trophy was designed in Europe and is modeled along the lines of the champion trophies in the top European leagues.

Since the league inception, a total of five clubs have been crowned champions of the I-League. Of the 21 clubs to have competed since the inception of the I-League in 2007, the teams to have won the title are Mohun Bagan A.C. (1), Bengaluru FC (1), Churchill Brothers (2), Dempo (3), and Salgaocar (1).