India I-League

In 1996, the first domestic league was started in India, known as the National Football League, in an effort to introduce professionalism in Indian football. Despite that ambition, that has not been achieved to this date. During the National Football League days, the league suffered from poor infrastructure and unprofessionalism from its clubs. One of the clubs in the league, FC Kochin, went defunct in 2002 after it was revealed that the club had not paid salaries since 2000, after making up 2.5 crores of losses in a season.

After a decade of decline with the National Football League, the All India Football Federation decided it was time for a change. This resulted in the modern day iteration of the top-tier in India.

After the 2006–07 NFL season, it was announced that it would be rebranded as the I-League for the 2007–08 season. The league's first season consisted of eight teams from the previous NFL campaign and two teams from the 2nd Division to form a 10 team league. Oil and Natural Gas Corporation (ONGC), the title sponsors of the previous NFL, were named as the title sponsors of the I-League before the league kicked off in November 2007. The league also announced a change in their foreign-player restrictions with the new rule being that all the clubs could sign four foreigners – three non-Asian and one which must be Asian. The league also announced that, for the first season, matches will be broadcast on Zee Sports.

The original ten clubs in the I-League's first season were Air India, Churchill Brothers, Dempo, East Bengal, JCT, Mahindra United, Mohun Bagan, Salgaocar, Sporting Goa and Viva Kerala.

The first I-League match took place on 24 November 2007 between Dempo and Salgaocar. The match, which took place at the Fatorda Stadium in Margao, ended 3–0 in favour of Dempo with Chidi Edeh scoring the first goal in league history in the third minute. After eighteen rounds it was Dempo who came out as the first champions in the I-League. Viva Kerala and Salgaocar, however, ended up as the first two teams to ever be relegated from the I-League.

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 2 to make the expansion possible. This however brought up early concerns over how "national" the I-League was. The 2008–09 season would see eleven of the twelve teams come from three different cities. The previous season saw all ten teams come from four different cities. Bhaichung Bhutia, then captain of the India national team, said that it was the federations job to spread the game across the country and that it needed to happen.

Regardless of the early criticism, the I-League went on as scheduled and once the 2008–09 season concluded. it was Churchill Brothers who came out on top. Then, before the 2009–10 season, the league was once again expanded from 12 teams to 14. In order to make this happen Salgaocar, Viva Kerala, Pune, and Shillong Lajong were all promoted from the 2nd Division to the I-League. This helped the I-League retain some criticism about how national the league was as now the league would be played in seven different cities/states: Goa, Kerala, Kolkata, Mumbai, Pune, Punjab, and Shillong.

After the 2009–10 season it was Dempo who came out on top for the second time in I-League history.

On 9 December 2010 the All India Football Federation signed a 15-year, 700-crore deal with Reliance Industries and International Management Group of the United States. The deal gave IMG-Reliance exclusive commercial rights to sponsorship, advertising, broadcasting, merchandising, video, franchising, and rights to create a new football league. This deal came about after the AIFF ended their 10-year deal with Zee Sports five years early.

Two months later, on 8 February 2011, it was reported that twelve of the fourteen I-League clubs held a private meeting in Mumbai to discuss the ongoing issues related to the league. It was never revealed what was exactly talked about at this meeting. Then, on 22 February, it was announced that the same twelve I-League clubs that attended the meeting would not be signing the AFC–licensing papers needed to play in the I-League. The reasoning for this was because the I-League clubs were not happy over the fact that IMG-Reliance had so far done nothing to promote the I-League and that they demanded the I-League be made a separate entity from both the AIFF and IMG-Reliance. At this time however there were rumours that IMG-Reliance had been planning on revamping the I-League along the same lines as Major League Soccer of the United States for the 2012–13 season.

On 11 March 2012, following the disbanding of two former I-League clubs – JCT and Mahindra United, it was announced that the I-League clubs would be forming their own organization known as the Indian Professional Football Clubs Association (IPFCA) in order to safeguard their interest and promote football in India. Every club, except for HAL and AIFF–owned Pailan Arrows, joined the newly formed organization. Soon after, it was announced that there would be a meeting held between the AIFF, IMG-Reliance, and the IPFCA on 20 April 2012. In this meeting, IMG-Reliance would present their plan on how they would grow the I-League but the meeting never occurred for reasons unknown.

Then, on 4 May 2012, the AIFF hosted the last ad hoc meeting – an annual meeting between the AFC and AIFF to assess the growth of Indian football. The AFC president at the time, Zhang Jilong, was also in attendance at this meeting. It was reported that the IPFCA would use this meeting to voice their displeasure at the AIFF and IMG-Reliance but the association never showed up at the meeting.

On 18 June 2012 the IPFCA was officially sanctioned under the Society's Act of 1960.

Despite the ongoing war between the AIFF, IMG-Reliance, and the IPFCA, the league did manage to improve its product on the field and awareness did increase during this period. It all started when the India national team participated in the AFC Asian Cup in 2011 for the first time in 27 years. Despite being knocked-out in the group stage after losing all three of their games, India came back home more popular than ever. Subrata Pal, of Pune gained the most popularity after his impressive performances in goal for India during the Asian Cup. At the same time, before the Asian Cup, Sunil Chhetri became the second Indian footballer in the modern footballing era to move abroad when he signed for the Kansas City Wizards in Major League Soccer in 2010. He also became the first exported Indian from the I-League.

The league was then given a major boost from its main derby, the Kolkata derby, between East Bengal and Mohun Bagan. On 20 November 2011, 90,000 people watched at the Salt Lake Stadium as Mohun Bagan defeated East Bengal 1–0. The league also saw more expansion to others areas with the promotion of United Sikkim from the 2nd Division, however, their reign was short lived as financial troubles saw them relegated the next season.

Meanwhile, while the league continued to grow, so did the players' demand. During this period plenty of Indian players were wanted on trial by foreign clubs, mainly in Europe. After his return from MLS, Sunil Chhetri and international teammate Jeje Lalpekhlua were called for trials at Scottish Premier League side Rangers in 2011. Subrata Pal had trials at RB Leipzig before finally signing for Vestsjælland in 2014. And Gurpreet Singh Sandhu underwent trials at then Premier League side Wigan Athletic and finally signing for Stabæk Fotball, Norway in 2014.

At the same time, as Indian players demand abroad increased, the demand for higher quality foreigners in the I-League also increased. Former A-League player of the year and Costa Rican international Carlos Hernández signed with Prayag United before the 2012–13 season from the Melbourne Victory. Lebanese international Bilal Najjarine also signed with Churchill Brothers in 2012.

On 18 May 2016, IMG–Reliance, along with the AIFF and I-League representatives met during a meeting in Mumbai. At the meeting, it was proposed that starting from the 2017–18 season, the Indian Super League becomes the top-tier football league in India while the I-League gets relegated to the second tier, but the idea was not entertained by the I-League representatives.

In 2017, FIFA and the AFC had appointed a committee to look at the footballing landscape in the country which was in disarray due to two simultaneous leagues running together, and come up with solutions to re-establish a singular league pyramid which would be acceptable for everyone. In the month of June, IMG–Reliance, the AIFF and the I-League representatives, met with the AFC in Kuala Lumpur in order to find a new way forward for Indian football. The AFC were against allowing the ISL as the premier league in India while the clubs like East Bengal and Mohun Bagan wanted a complete merger of ISL and I-League. A couple weeks later, the AIFF proposed that both ISL and I-League run simultaneously on a short–term basis with the I-League champions retaining the spot for the AFC Champions League qualifying stage, while the AFC Cup qualifying stage spot going to the ISL champions. The proposal from the AIFF was officially approved by the AFC on 25 July 2017, with the ISL replacing the domestic cup competition, the Federation Cup.

On 14 October 2019, the AFC held a summit in Kuala Lumpur, chaired by the AFC Secretary General Windsor John, which involved key stakeholders from the AIFF, the FSDL, the ISL and the I-League clubs, and other major stakeholders to propose a new roadmap to facilitate the football league system in India. Based on the roadmap that was prepared by the AFC and the AIFF at the summit and was finally approved by the AFC Executive Committee on 26 October in Da Nang, in 2019–20 season, ISL will attain the country's top-tier league status, allowing the ISL premiers to play AFC Champions League and the I-League champions to play AFC Cup. In addition, starting with the 2022–23 season, I-League will lose the top-tier status, wherein the champion of the I-League will stand a chance to be promoted to the ISL with no participation fee. In its recommendation for 2024–25, it was agreed to fully implement promotion and relegation between the two leagues, and abolition of parallel league system.