[13] Soon after the appointment of Subedar-major Sailen Basu as the secretary, the club adopted European playing methods and players underwent rigorous physical training and followed austere fitness regime similar to that in the army.
[18][19] They battled out against the professionally equipped teams of St. Xavier's College, Calcutta Rangers Club, Rifle Brigade and Middlesex Regiment to reach the IFA Shield final without conceding a goal.
[29] On 8 August 1921, the club played its first match against East Bengal in the Coochbehar Cup semi-final, which ended in a goalless draw, but Mohun Bagn went on to beat them in the replay by 3–0 and gave rise to the Kolkata Derby.
[38] 1935 saw a great change in Mohun Bagan's tradition of playing with bare-feet when on the behest of Abdul Hamid, a renowned player from Quetta, the club decided to use boots mandatorily for the first time.
[42][36][37][43] In the late-1930s both Umapati Kumar and Gostha Pal retired, but the squad got competent reinforcements – Anil Dey in half back position and Satyen 'Mana' Guin in attack, who a right winger was nicknamed "Racing Deer" for his speed along the flanks.
[46] In 1945, George Curtis, who was an Arsenal player stationed in India as a part of Royal Air Force in the World War II, took charge of the team on request as a mentor for a brief stint.
Despite acquiring the services of some of the famed players the club failed to dominate in major tournaments, where they were regularly outshined by the Pancha Pandav led East Bengal and Syed Abdul Rahim's Hyderabad City Police team.
Mohun Bagan won the CFL in 1951 after a wait of seven years, the IFA Shield in 1952, and its first Durand Cup in 1953 by 4–0 against National Defence Academy team in the presence of President Dr. Rajendra Prasad.
[65] With foreign recruits becoming common in East Bengal, Mohun Bagan failed to beat them even once between 1969 and 1974 and lost to their arch-rivals in Durand Cup and IFA Shield finals multiple times.
By 1976 Mohun Bagan assembled their best team in years under the helm of Chandra Madhab Roy with the inclusion of a host of players from their two local rivals, including the attacking brothers–Mohammed Habib and Mohammed Akbar, and Subhash Bhowmick.
[70] With a domineering squad, Mohun Bagan yet suffered a shocking defeat of 1–0 against ITI team in the inaugural Federation Cup, which became the most prestigious title in the country, and also lost the first Derby of that year.
On 24 September 1977, through the efforts of Dhiren Dey, Mohun Bagan played a friendly match against the American club New York Cosmos which featured Brazilian World Cup winners like Pelé and Carlos Torres, and Serie A icon Giorgio Chinaglia.
After the further additions of Manas Bhattacharya and Shyamal Banerjee, Mohun Bagan continued their dominant run in 1978, consisting of a CFL win with record 78 goals in 22 matches and a Federation Cup joint-win with East Bengal.
[76] As a result, a host of new players were recruited in 1984, and the most notable names being Prasanta Banerjee, Babu Mani and Tanumoy Basu, and that led to major successes, including Durand Cup and the Calcutta League title.
They qualified for ACC once again for the 1988–89 season by winning the 1987 Federation Cup and displayed outstanding performance in the group stage, including a 6–0 defeat of Pakistani team Crescent Textiles Mill with a hat-trick from Sisir.
With a record 131,000 attendance at Vivekananda Yuba Bharati Krirangan, Mohun Bagan's defensive frailties were exposed by Bhaichung Bhutia, who scored a hattrick in a 4–1 victory for East Bengal.
Renowned internationals like Uzbek striker Igor Shkvyrin, Nigerian forward Stephen Abarowei, Thai full-back Dusit Chalermsan and Kenyan defender Samuel "Pamzo" Omollo, and Brazilian José Ramirez Barreto joined the club.
[99] With internal problems slowly subsiding, Mohun Bagan assembled a strong side in 2006 that included Barreto and Bhaichung's return, along with a combative Brazilian midfielder Douglas Silva.
[101] In 2008, Mohun Bagan players got the opportunity to play against German icon Oliver Kahn in his official testimonial match for Bayern Munich, which also featured Brazilian star Zé Roberto.
Some of the foreign stars recruited during this period were Odafa Onyeka Okolie from Churchill Brothers, with a record salary of ₹1.4 crores per year in 2011, Muritala Ali from Mahindra United and Tolgay Özbey from East Bengal.
[109] However, on 15 January 2013, Mohun Bagan appealed against the decision and were reinstated, but a hefty amount was fined, their officials were suspended from all the AIFF meetings for a year and, the team would start with 0 points and would play out only the remaining 16 fixtures in the league.
[137][138][139][140][141][142] In May 2023, Lucknow Super Giants, a RPSG Group owned Indian Premier League franchise, sported a special Green-Maroon jersey in their away fixture against Kolkata Knight Riders to pay tribute to the century-old legacy of Mohun Bagan.
[148][149] With Habas back to his former coaching duties and significant goal contributions from the Aussie duo – Petratos and Cummings, Mohun Bagan went on to win their first ISL Premiership in a final matchday decider against Mumbai City.
Initially the club crest consisted of the picture of a Royal Bengal tiger laying either amidst a dense jungle, probably indicating the famous Sundarbans, or simply a palm tree.
[155] A multi-purpose stadium owned by the Government of West Bengal under Youth Affairs and Sports Department, the VYBK primarily hosts football matches, apart from occasional track and field events.
[158] After coming in as the principal investor, KGSPL renovated the stadium in the lines of Vivekananda Yuba Bharati Krirangan with artificial turf and upgraded amenities so that it can be used for practice and home matches in Indian Super League and other big tournaments as and when required.
[161] Their grand reception when, by some estimates, over 200,000 fans gathered to greet the 2014-15 I-League clinching squad (on their way back to Kolkata from Bengaluru) has been dubbed as "legendary", "unparalleled" and "surreal" by the press as well as football historians.
[165][166] The fanclubs have regularly taken part in social causes, such as holding periodic blood donation camps, distributing clothes and blankets to the poor or collecting funds and providing relief during the COVID-19 lockdown and Cyclone Amphan.
[167] In an unprecedented event, Mohun Bagan and its arch-rival East Bengal's respective fanclubs called for a unified mass protest on 18 August 2024, after the cancellation of the scheduled derby of Durand Cup on security grounds fearing a civil unrest surrounding the rape and murder incident at R.G.
One such instance was in Raja Memorial Shield final played on 6 August 1937 at the common ground of both the clubs (Vivekananda Yuba Bharati Krirangan), where Mohun Bagan beat East Bengal FC 4–0 and Asit Ganguly scored three goals in that match.