The ultras movement in Siena began in the mid-1970s with the formation of the Siena Club Fedelissimi, Boys, and Brigate Bianconere. Subsequently, groups like the Ultras and Fighters Black & White emerged, dominating the scene towards the late 1970s. By 1979, a merger of Ultras, Fighters Black & White, and Brigate Bianconere led to the creation of Ultras Fighters, who maintained control over the curva throughout the 1980s, peaking in 1985/86. However, frequent clashes with rival fans and the police resulted in severe measures that significantly weakened the group.
During the decline, the extreme-right Falange d’Assalto, later renamed Robur Ghibellina, and the Mods disbanded. The Ultras Fighters were supported by the younger Armata Ghibellina, but the scene became increasingly disorganized. In 1991, leveraging a temporary surge in the team’s performance, the Gioventù Ghibellina was founded, relegating the U.F.S. to a minor group of ex-veterans. Poor team results and conflicts with the management further alienated fans, leading to the collapse of Gioventù Ghibellina and other smaller groups.
For two years, there was no organized support, only ongoing protests until 1993 when the younger fans, with the old guard’s approval, revitalized the Ultras Fighters as the leading group in the curva. Noteworthy was the introduction of the “ad ossi” banner in the 1983/84 season, and the 1990 formation of the politically named Gruppo d’Azione.
In 1997, a splinter from U.F.S. formed Robur Alcool, a group with a playful, non-ultras approach, still rooted in local traditions. In 1999, the Teste Matte emerged from a younger faction of U.F.S., followed by Centro Storico, comprising active contradaioli, and G.A.R.S. 1260 (Gruppo Antica Repubblica Senese), which had a short-lived presence.
The promotion to Serie B in 2000 ignited a new wave of enthusiasm and the emergence of numerous small groups. This excitement culminated in 2003 with Siena’s historic promotion to Serie A, filling the stadium almost every Sunday.
In 2007, following the murder of Inspector Filippo Raciti in Catania, the long-standing Ultras Fighters Siena 1979 banner was replaced by Ghibellini Robur 1904. The Curva Robur 1904 group then took over the curva, supported in the 2010/11 season by L.S.B.-Skala 40 (La Siena Bene). Despite being the most numerous and active group, they handed over leadership to the dynamic Vecchi Ultras in 2012, bringing fresh energy to the curva.
In the 2014-2015 season, the Robur supporters set a then-record for Serie D season tickets, later surpassed by Parma in the 2015-2016 season.
In 2016, a group of young fans established Figli Di Siena, who currently lead the Curva Lorenzo Guasparri, named after a devoted Siena fan who passed away prematurely.
The Siena supporters are twinned with the supporters of Udinese and Pistoiese. The bond with the Friulians, in particular, connects both the supporter groups and the clubs. A friendship links the Vecchi Ultras group with Bologna’s Beata Gioventù, due to their common rivalry with Fiorentina. Another friendship connects the Tuscan supporters with those of Como. Finally, in recent years, the group Noi non tesserati has formed a friendship with Maceratese’s Curva Just.
The main rivalry, especially felt by a large portion of Siena fans who champion “Ghibellinism,” is with the Fiorentina supporters. The match against Fiorentina is called the “Guelphs-Ghibellines derby,” due to two historic battles between the cities: the Battle of Montaperti in 1260 (celebrated by Siena’s Ghibellines) and the Battle of Colle di Val d’Elsa in 1269 (celebrated by Florence’s Guelphs, then allied with the people of Colle di Val d’Elsa). However, it is important to note that both Siena and Florence were internally divided between Guelphs and Ghibellines during the Middle Ages.
There has been a rivalry with Livorno since the 1950s.
Another strong rivalry exists with Roma supporters, as twice during matches between the two teams, the games were suspended due to smoke bombs thrown by Roma fans, along with some stabbings and occasional threatening banners against Siena fans displayed in Roma’s Curva Sud. On September 13, 2009, during a Siena-Roma match that ended 1-2, Siena supporters chanted offensive stadium songs towards Daniele De Rossi’s father-in-law, Massimo Pisnoli, who had been murdered the previous year, and towards De Rossi himself. However, this incident did not lead to acts of violence. The tensions between the supporters and De Rossi began in November 2004 when the Roma player caused a severe injury to Siena player Andrea Ardito.
There has always been strong antipathy between Siena and Empoli supporters, with many violent incidents leading to arrests and charges after clashes between the two sets of fans.
There is also a significant rivalry with Perugia fans, marked by numerous clashes between the two groups, in what is almost considered a derby. The two sets of fans faced each other even in Serie A in the 2003-2004 season.
Important regional rivalries exist with Arezzo and Grosseto supporters. The first is a historical rivalry rooted in the Middle Ages. Siena was defeated by the Guelphs of Colle di Val d’Elsa and Florence in 1269 in the Battle of Colle di Val d’Elsa. This defeat led Siena to abandon the Ghibelline faction, becoming Guelph and incurring the wrath of Arezzo’s Ghibellines, who called the Sienese “traitors.” A year after suffering a painful and bloody defeat to the Ghibellines of Arezzo on June 26, 1288, at Pieve al Toppo, on June 11, 1289, in the famous Battle of Campaldino, Guelph Siena, allied with Florence, defeated Ghibelline Arezzo. Arezzo, leading the Ghibelline faction under Uguccione della Faggiola, avenged itself by defeating the Florentine and Sienese Guelphs on August 29, 1315, in the Battle of Montecatini. The second rivalry has developed continuously from the historical rivalry between the city of the Palio and the Maremma capital, already existing in the medieval era when Grosseto was under Siena until the fall of the Sienese Republic.