Foundation and early years

Frosinone Calcio was founded on 5 March 1906 under the name Unione Sportiva Frusinate. The colours of the team were originally red and blue which were later changed to the current yellow and blue. By year of foundation, the Frosinone company ranks third among those still active in the Lazio, after "S.S. Lazio" (1900) and "S.S. Formia" (1905)

On 5 March 1906, the lawyer Leone Vivoli, future mayor of Frosinone, gave birth to the "Unione Sportiva Frusinate". The objectives in the articles of association included the diffusion of various sports and among them there was explicitly included football.

On 14 March 1906 Il Messaggero reported the news as follows: «Made up of about thirty effective members, it was formed in our city with premises in Corso Vittorio Emanuele n.2 [NB: today Corso della Repubblica] , a Frosinone sports club chaired by the lawyer Leone Vivoli. Councilors: student R. Giovannelli – accountant G. Tora – receiver G. Pesci – engineer E. Marzi – Inspector E. Toscano – Secretary Gabriele Antonucci – Sports Director Gerardo Bodin de Chadelard».

The presence of competitive football-related activities is demonstrated by some documents immediately following the signing of the company statute, including a photo dating back to 1907, taken from the Bottoni archive, which shows a youth team of Frosinone footballers probably aged between 10 and 12 years.

Il Messaggero underlined, in the edition of 1 February 1907, the feedback acquired in a short time by the new sports association in the city: «This sports union which has as its main purpose physical education, given the ever increasing number of members, has occupied new premises [...] The brilliant meeting is frequented by the most respectable people of the city who praise and encourage the healthy development of the Association».

The first corporate colours, as specified in the articles of association in article IV, were red and blue, taken from the city coat of arms.

It showed a rampant lion on a red background and a blue cross band with the motto "Bellator Frusino", given by Sillo Italico, when the city refused to surrender to Hannibal's armies. Given the cost of the uniforms of the time, it is unlikely that the rossoblu uniform was worn from the beginning.

Article III of the Articles of Association stated, with a rather modern approach for the time, that the sports association abstained from any activity of a political and religious nature

The first playing field adopted by the company was located in Frosinone along today's via Cicerone (at the time called via Casilina Nord) near the municipal villa, while the historic "Stadio Matusa" (which would have resisted, with modifications and extensions subsequent, until 2017) was built only in 1932.

The same club, however, has conventionally chosen as its date of origin not the foundation of the sports club (5 March 1906), as is widely consolidated practice with illustrious examples such as the Genoa (1893) and Milan (1899)(sports clubs which included "cricket" and "football") but rather the change of name in "CXIX Legio M.V.S.N. Frosinone" and his consequent affiliation to the FIGC which took place over twenty years later, on 19 September 1928.

This method appears very unusual if we consider the establishment of many other sports clubs, such as the "Società Podistica Lazio" (which, founded in 1900, joined the FIGC in 1908 and set up a football section only in 1910) or the "Genoa Cricket and Football Club" (which became affiliated five years after being created as a sports club).

In fact, even before the change of company name induced by the fascist regime, the U.S. Frusinate had already obtained affiliation with the FIGC in 1923 and had been involved in competitive activity by appearing in the federal ranks of the championship of the Fourth Division Lazio 1923–1924 in group B. The Ciociaro team in that period at an organizational level was coordinated by Augusto Diamanti, a reference figure who was in charge of the company's executives. In the starting lineup, among others: Biagi (goalkeeper), Armando Niro, Nobili, Magni, Luigi Diamanti, Dante and Giulio Toscani, Aldo and Renato Calmanti (the latter would also be captain for many years to come, also playing in the Prima Division until the mid-1930s, when he suddenly died of a heart attack at the age of 29).

The activity of the Frosinone team at the beginning of the 1920s is testified by the sports news of the time, including an article from 1922 published in La Gazzetta dello Sport. It reports the description of the match played on 28 June 1922, at the Madonna della Neve football field in Frosinone, between the 59 º fanteria Frosinone and the U.S. Frusinate. The official meeting, directed by the referee Carlo Magni and played in the presence of the mayor Piero Gizzi and the military authorities, was valid for the assignment of the Comune di Frosinone award. The victory went to the selection of the Army for six goals to zero.

Experienced players such as Vincenzo Fresia, four-time champion of Italy with Pro Vercelli and former number 9 jersey in the national team were lined up in the latter's row. Who served as a lieutenant in Frosinone in the 59th Infantry Regiment

In another match played on 27 August of the same year, the Frosinone team reached the Rossoneri of the C.S. Alatri thanks to a marking by its captain Renato Calmanti.

At that time the presence of category players in the military selection stimulated the competitive activity of the Unione Sportiva Frusinate, which was deployed on the field with the white and blue social colors. After affiliation to the FIGC in 1923 and registration in the IV Lazio Division, in 1925 the Unione Sportiva Frusinate passed the baton to the new Società Sportiva Alba Frusinate.

At the end of the decade sports activity in Frosinone received new impetus from the fascist policies of incentives for physical exercise and sport, as well as the economic and political expansion that the city underwent following the establishment of the new province of which it became the capital in 1927. In this context, on 19 September of the following year the company changed its name again to Gruppo Sportivo CXIX Legione M.V.S.N. Frosinone , thus joining again the Italian Football Federation. On 25 September the team registered for the third division group B championship.

On 17 October 1929 the sports newspaper Il Littorale reported the news of the affiliation of the new Polisportiva Bellator Frusino to the FIGC. The sports club, which collected the inheritance from the CXIX Legione M.V.S.N. Frosinone , was led by Pier Luigi Tinelli. The team participated in the III Division championship, group C, while the following season was included in group B

The club, later named Bellator Frusino, managed to reach the National First Division in 1934. The figure of president Emilio Frongasse was crucial in this period. In the later half of the thirties, Bellator Frusinate disbanded, and was replaced by FF.GG. Frosinone which played its football in an interprovincial tournament.

All the championships were suspended during the Second World War and the football club Frusinate disappeared.

The rebirth of Frosinone occurred in the 1945–1946 championship, the team competed in the Seconda Categoria championship and rose to Prima Categoria the following year, and later, following an excellent championship season, managed to gain promotion into Serie C-Lego Centro. From 1948 to 1949 to 1951–52, the Canarini competed in the Promozione-Interregionale della Lega Centro championship, and were included in the new Quarta Serie championship during the summer of 1952.

From 1952 to 1958, for six consecutive years, the Canarini competed in the Quarta Serie Championship, with their highest finish being fourth place, which was achieved in 1953. The most significant match this time was against Cosenza on 24 November 1957. Cosenza were playing for promotion but Frosinone took the lead (and duly won) with three minutes remaining.

The referee, struck by a Cosenza player, fell to the ground and was booed until the end of the game. Several episodes of violence then took place and the game was transformed into a "western". After leaving the stadium, the referee was chased for a few kilometers by some Frosinone supporters. Cosenza forwarded an appeal and the CAF overturned the result of the match. Frosinone expressed their resentment against the Lega for the injustice suffered and threatened to withdraw from the league. Following this, Frosinone missed the return fixture in Cosenza and other penalties by the Lega were imposed.

The most important people of this time were the presidents Domenico Ferrante and Angelo Cristofaro (one of the leading figures in the history of the club), a former coach Genta and players Azzoni, Gabriele, Diglio, Dini and Spinato.