The formal creation of the National Sinarquist Union, the name of which was chosen in deliberate contrast to "anarchism," was directly connected to the existence of the Catholic Church in the wake of the Cristero Rebellion. Its emergence and development can be interpreted in the light of the 1929 "Arrangements" between church and state that formally ended the uprising.
Sinarquism surfaced between 1929 and 1937, a period that both closed one phase and opened another in the context of Catholic participation in the Mexican political arena. Internal restructuring occurred within the Catholic Church, the immediate consequence of the new modus vivendi established in 1929. Thus, the church sought to reestablish its position in society through participation of the citizenry rather than through war.
The precursor of the UNS was the creation of the Legions, an organization of Catholics who disagreed with both the form and content of the "Arrangements." They originated in Guadalajara in 1933, metamorphosing into the Base, which would emerge in 1936 in Mexico City. The Base in turn was transformed into the UNS, which specialized in working within the campesino (peasant) sector during what would be the most critical years of the agrarian reforms undertaken by President Lázaro Cárdenas. The appearance of the UNS in 1937 must be seen in the context not only of the national situation but also the papal decision of Pius XI as revealed in the encyclical Firmissimam Constantia of March 28, 1937. According to the encyclical, Catholic political action must be limited to that permitted for citizens, in other words subject to the laws of a legitimate civil government. Thus the official policy of the church promoted indirect action, hence the importance given at the time to the formation of the Mexican Catholic Action movement orientated to the evangelization of the lay population. Thus, main recruitment centers of the sinarquist movement between 1937 and 1945 were located in areas where Catholic Action had become most quickly rooted, such as the central states of the Republic.
The formation and future internal conflicts of sinarquism would echo the two currents that composed it. On one hand were the dissidents who saw the "Arrangements" as the church's defeat by the state. This group was headed by Manuel Romo de Alba, founder of the Legions (which replaced the League for the Defense of Religious Freedom), and taken further by its most charismatic leader, Salvador Abascal. On the other hand were the Vatican interests and a minority sector of the Mexican episcopal hierarchy who believed that the political activity of the church had metamorphosed into a subordinate force in the context of the secular state. Sinarquism was thus born under a double star, that of intransigence and conciliation.
The UNS was founded on May 23, 1937, in León, Guanajuato, as a fusion between the Eighth Division of the Legions commanded by José Antonio Urquiza located in the Bajfo and the eleventh Section of the associations of the Base, which was geared to working with the campesinos. Sinarquism was integrated by three types of militant: former Cristero Rebels (especially sympathizers), former League members, and new Catholic Action militants. These three sectors would represent the three currents in Sinarquism. The civic current was in line with the new directions of Catholic Action, which converted this division into pressure groups, their important leader being Antonio Santa Cruz. This movement would practically disappear toward the 1950s. The second was the mystical or intransigent current, with Salvador Abascal as its most celebrated leader, which would later form the basis of different ultra-rightist groups. Finally, there was the civic-political or intermediate current, which accepted the new bases for action established by the Catholic Church but fought at the same time to solidify its own autonomy, particularly against the alternative represented by the Partido de Acción Nacional (PAN, or National Action Party). This current was headed initially by Manuel Torres Bueno, among others, and later by Juan Ignacio Padilla, who after 1944 would try several times to transform the UNS into a political party.
The politico-electoral branch of Sinarquism that would take over the movement from 1945 had great affinities with the PAN. This section founded the Partido Fuerza Popular (PFP, or Popular Strength Party) in 1946, taking advantage of the political reforms promoted by President Manuel Avila Camacho. This time the UNS militancy was dedicated to that of the party. Their registration was canceled on January 31, 1949, because of the demonstration at the Juárez monument in Mexico City in December 1948, which turned popular feeling against them. In 1953 the UNS created the Partido de Unidad Nacional (PUN, or Party of National Unity) which disappeared once its registration as a political party was obtained in 1954. In 1963, nearly a decade later, Sinarquism was incorporated into the Partido Nacionalista de Mexico (PNM, or Mexican Nationalist Party), founded in 1957 by a former cristero leader. The PNM split into separate groups as a