Mexican Revolution (1910–20) remains the largest conflict in Mexican history. The overthrow of dictator
Porfirio Díaz unleashed disorder, with many contending factions and regions. The Catholic Church and the Díaz government had come to an informal modus vivendi whereby the State did not enforce the anticlerical articles of the liberal
Constitution of 1857, but also did not repeal them. Having a change of leadership or a wholesale overturning of the previous order was potentially a danger to the Church's position. In the democratizing wave of political activity, the National Catholic Party (Partido Católico Nacional) was formed.
Francisco Madero was overthrown and assassinated in a February 1913 military coup led by Gen.
Victoriano Huerta, bringing back supporters of the Porfirian order; with the ouster of Huerta in 1914, the Catholic Church was the target of revolutionary violence and fierce anticlericalism by many Northern revolutionaries. The
Constitutionalist faction won the revolution and its leader,
Venustiano Carranza, had a new revolutionary constitution drawn up. The
Constitution of 1917 strengthened the anticlericalism of the previous document. Neither President Carranza (1915–20) nor his successor, Gen.
Alvaro Obregón (1920–24), enforced the anticlerical articles. The Calles administration (1924–28) felt its revolutionary initiatives and legal basis to pursue them were being challenged by the Catholic Church. To destroy the Church's influence over the Mexican people, anti-clerical laws were instituted, beginning a ten-year religious conflict that resulted in the death of thousands of armed civilians. On the opposing side was an armed professional military sponsored by the government. Calles’ Mexico has been characterized by some as an
 and his program as being one to eradicate religion in Mexico.
Crisis in Church–State Relations
A period of peaceful resistance to the enforcement of the anticlerical provisions of the constitution by Mexican Catholics brought no result. Skirmishing broke out in 1926 and violent uprisings began in 1927.
 The rebels called themselves Cristeros, invoking the name of
Jesus Christ under the title of "Cristo Rey" or Christ the King. The rebellion is known for the
Feminine Brigades of St. Joan of Arc, a brigade of women who assisted the rebels in smuggling guns and ammunition, and for certain priests who were tortured and murdered in public (and later
Pope Saint John Paul II). The rebellion eventually ended by diplomatic means brokered by
U.S. Ambassador to Mexico
Dwight Whitney Morrow, with financial relief and logistical assistance provided by the
Knights of Columbus.
The rebellion attracted the attention of
Pope Pius XI, who issued a series of
papal encyclicals between 1925–37. On December 11, 1925, the
Quas primas, instituting the
Feast of Christ the King. On November 18, 1926, he issued
Iniquis afflictisque (On the Persecution of the Church in Mexico), denouncing the violent anti-clerical persecution in Mexico.
 Despite the government's promises to the contrary, it continued the persecution of the Church. In response, Pius issued
Acerba animi on September 29, 1932.
 As the persecution continued he issued Firmissimam Constantiam and expressed his opposition to the "impious and corruptive school" (p. 22) while granting papal support for
Catholic Action in Mexico for the third consecutive time with the use of
plenary indulgence on March 28, 1937.
The Mexican Constitution of 1917
Political Constitution of the United Mexican States was drafted by the
Constitutional Congress convoked by
Venustiano Carranza in September 1916, and it was approved on February 5, 1917. The new constitution was based in the
previous one instituted by
Benito Juárez in 1857. Three of its 136 articles—Article 3, Article 27 and Article 130—contain heavily secularizing sections, restricting the power and influence of the Roman Catholic Church.
The first two sections of
article 3 state: "I. According to the religious liberties established under article 24, educational services shall be secular and, therefore, free of any religious orientation. II. The educational services shall be based on scientific progress and shall fight against ignorance, ignorance's effects, servitudes, fanaticism and prejudice".
 The second section of
article 27 states that: "All religious associations organized according to article 130 and its derived legislation, shall be authorized to acquire, possess or manage just the necessary assets to achieve their objectives".
The first paragraph of
 states that: "The rules established at this article are guided by the historical principle according to which the State and the churches are separated entities from each other. Churches and religious congregations shall be organized under the law".
It also provided for obligatory state registration of all churches and religious congregations, and placed a series of restrictions on priests and ministers of all religions (ineligible to hold public office, to canvas on behalf of political parties or candidates, to inherit from persons other than close blood relatives, etc.).
 The article also allowed the state to regulate the number of priests in each region—even reducing the number to zero—and forbade the wearing of religious garb and excluded offenders from a trial by jury. Venustiano Carranza declared himself opposed to the final draft of Articles 3, 5, 24, 27, 123 and 130, but the Constitutional Congress contained only 85 conservatives and centrists close to Carranza's rather restrictive brand of "liberalism"; against them were 132 more radical delegates.
Article 24 states that: "Every man shall be free to choose and profess any religious belief as long as it is lawful and it cannot be punished under criminal law. The Congress shall not be authorized to enact laws either establishing or prohibiting a particular religion. Religious ceremonies of public nature shall be ordinarily performed at the temples. Those performed outdoors shall be regulated under the law".
Background to Rebellion
Violence on a limited scale occurred throughout the early 1920s, but never rose to the level of widespread conflict. In 1926, following passage of stringent
anticlerical criminal laws and enforcement of these so-called Calles Laws (named for Mexican President Plutarco Elías Calles) coupled with peasant revolts against land reform in the heavily Catholic
Bajio and clampdown on popular religious celebrations such as fiestas, scattered guerrilla operations coalesced into a serious armed revolt against the government.
Catholic and anticlerical groups turned to terrorism. Of the several uprisings against the Mexican government in the 1920s, the Cristero War was the most devastating and had the most long-range effects. The diplomatic settlement of 1929 brokered by the US Ambassador to Mexico between the Catholic Church and the Mexican government was supported by the Vatican. Although many Cristeros continued fighting, they no longer did so with the tacit support of the Church. Persecution of Catholics and anti-government terrorist attacks continued into the 1940s, when the remaining organized Cristero groups were incorporated into the Sinarquista Party.
The Mexican Revolution of 1910 was originally fought against longtime autocrat
Porfirio Díaz and in favor of the demand by the mass of peasantry for land. However, the late revolutionary leader Plutarco Elias Calles took radically anti-Catholic stances, despite the Church's overwhelming support from the people.
Francisco I. Madero was the first revolutionary leader. Madero was elected president in November 1911 but was overthrown and executed in 1913 by the counterrevolutionary Gen.
Victoriano Huerta. When Huerta seized power after Madero's assassination, Archbishop Ruiz y Flores from Morelia published a letter condemning the coup and distanced the Church from Huerta. The National Catholic Party newspaper, representing the views of the bishops, attacked Huerta severely and, as a result, the new regime jailed the President of the NCP and halted the publication of the newspaper. Nevertheless, some members of the National Catholic Party decided to participate in Huerta's regime, such as Eduardo Tamariz.
 The revolutionary generals
Francisco Villa and
Emiliano Zapata—who vanquished Huerta's federal army under the
Plan of Guadalupe—had friendships with the Catholics and local parish priests who aided them,
 but they also blamed high-ranking Catholic clergy for supporting Huerta.
Carranza was the first president under the new Constitution, but he was overthrown by one-time ally
Álvaro Obregón in 1919, who took over the presidency in late 1920. Obregón effectively applied the secularist laws emanating from the constitution only in areas where Catholic sentiment was weakest. This uneasy "truce" between the government and the Church ended with the 1924 hand-picked succession of an atheist,
Plutarco Elías Calles.
Jacobins, supported by Calles' central government, went beyond mere anti-clericalism and engaged in secular anti-religious campaigns to eradicate what they called "superstition" and "fanaticism", which included the desecration of religious objects as well as the persecution and murder of the clergy.
Calles applied the anti-clerical laws stringently throughout the country and added his own anti-clerical legislation. In June 1926 he signed the "Law for Reforming the Penal Code", known unofficially as the "
Calles Law." This provided specific penalties for priests and individuals who violated the provisions of the 1917 Constitution. For instance, wearing clerical garb in public (i.e., outside Church buildings) earned a fine of 500 pesos ($250 U.S. per the historical exchange rate); a priest who criticized the government could be imprisoned for five years.
 Some states enacted oppressive measures.
Chihuahua enacted a law permitting only a single priest to serve the entire Catholic congregation of the state.
 To help enforce the law, Calles seized church property, expelled all foreign priests and closed the monasteries, convents and religious schools.