ACF Fiorentina was founded in 1926 as AC Fiorentina after a merger between two rivals: 'Club Sportivo Firenze' and ' Palestra Ginnastica Libertas' and re-established in 2002 after a bankruptcy. The merger in 1926 was due to the wishes of the fascist regime, which didn't lie division in the same city. It wasn't only in Florence, where Fiorentina is from, these mergers happened, as Inter, Napoli and Roma also underwent these situations.
Fiorentina had a tough start but achieved promotion to Serie A in 1931. Before this a mistake ended in one of the most important values of the team: the team colours. Their first official kits where of red and white but due to a mistake in the washing room, the kits turned into a shade of purple. The fans loved the colour and has ever since been the official team colour.
In 1931 Fiorentina moved into their stadium: Stadio Artemio Franchi, which not should be confused with Siena's stadium of same name. The stadium was considered a masterpiece of engineering. The team tried to establish them at the top of Italian football but suffered relegation in 1938 - only to promote to Serie A the next season. The same season as they returned they won their first Coppa Italia. The team had difficulty in keeping up with this result due to World War II.
The good results returned in the start 1950's and they won their first Scudetto in 1955-56, beating AC Milan with 12 points. The year after the standings where reversed so Milan won ahead of Fiorentina, but Fiorentina still achieved a remarkable goal: they where the first Italian team to reach an European final. However they lost 2-0 in the European Cup to Alfredo di Stefano's Real Madrid. Fiorentina continued to be runner-ups the next three seasons before they won their second Coppa Italia and the first Cup Winner's Cup over Rangers in 1961. They failed to hold on to the top of Italian football before 1966 where they won one more Coppa Italia and also the Mitropa Cup.
In the 1968/69 season Fiorentina won their second, and to this date, last Scudetto beating Cagliari Calcio in the standings. On their way they won over Juventus in Turin on the second last match day. Viola didn't maintain their status as a top team in the 1970's, although they won the Anglo-Italian Cup in 1974 and Coppa Italia in 1975. This was mainly due to the fact that the team wanted a more youthful image, giving them the name Fiorentina Ye-Ye.
In 1980 the team was bought by Flavio Pontello, who changed the logo and anthem, to big annoyance for the fans. However the fans could enjoy bigger names coming to the club, centralizing around Fiorentina legend Giancarlo Antognini, Daniele Massaro and Roberto Baggio but despite a rivalry in 1981-82 season with Juventus for the Scudetto, the team were never able to stay put in the top of Serie A.
In 1990 Fiorentina reached the final in the UEFA Cup, but only avoided relegation in Serie A. In the UEFA Cup final Fiorentina lost to Juventus, only creating an even bigger rivalry between the two teams. Not only did they loose the final: on the same day it was announced that Fiorentina fan favourite Roberto Baggio was sold to Juventus. President Pontello had economic difficulty and had to sell the club to film maker Mario Cecchi Gori.
The team didn't have immediate succes and was relegated for the first time since 1939 after the 1992-93 season. They stayed in Serie B for only one season where Claudio Ranieri took them back to the top flight. The team was now centralized around the young hope Rui Costa and Fiorentina icon Gabriel Batistuta. In 1995-96 season they won once again the Coppa Italia and finished 3rd. The next season Fiorentina became the first non-champion to win the Supercoppa Italiana, beating Milan 2-1 at San Siro. The late '90s gave the team moderate success, where they also partecipated in the UEFA Champions League. Under former Lazio star Roberto Mancini, the team won their sixth and last Coppa Italia in 2001. The year later however, the club died with terrible economic problems. They were first relegated to Serie B, but because of money situation the team wasn't granted a place here either and the team went bankrupt.
The team was re-established in 2002 as Associazione Calcio Fiorentina e Florentia Viola with Diego Della Valle as new owner. The team was admitted in the fourth tier, Serie C2, and got promoted to Serie C1 immediately the next season, after a huge contribution by Angelo di Livio, the only player to remain from the earlier team. However, Florentia Viola never got to play in Serie C1 due to the special 'Caso Catania' where Serie B was increased from 20 to 24 teams. Florentia Viola was allowed in the second tier due to 'sports merit' according to the Italian Football Federation.
In 2003 the team bought back the old logo and the name, now known as ACF Fiorentina. They only spended one season in Serie B as they got promoted due to play-offs where they beat Perugia 2-1 on aggregate. Their second season in Serie A, 2005-06, the team managed to end at fourth place thanks to coach Cesare Prandelli and 31 goalscorer Luca Toni. The teams bad period wasn't completely over though as the team was found guilty in it's involvement in the Calciopoli scandal. The team was first sent to Serie B but was reinstated in Serie A after an appeal. The team had to start with -19 points, later changed to -15. Despite this penilization the team amde it to the UEFA Cup, highly thanks to attacking duo Adrian Mutu and Toni.
Fiorentina has hereafter managed to qualify to the UEFA Champions League twice without big succes. Lazio legend Sinisa Mihajlovic took over the club in the 2010-11 season and brought the team to an ninth spot in his first season.