[10] The violence consisted of the killing of tens of thousands of people, including 6,832 Roman Catholic priests, the vast majority in the wake of the rightist military coup in July 1936, the Spanish nobility, small business owners, industrialists, conservative politicians, and known or suspected supporters of the right-leaning parties or the anti-Stalinist Left, and the desecration and arson attacks against monasteries, convents, Catholic schools, and churches.

[11] A process of political polarisation had already characterized the Second Spanish Republic; party divisions became increasingly embittered, and whether an individual continued practising Catholicism was seen as a sign of partisan loyalty.

[16] These attitudes and policies attracted harsh criticism at the time, even from fellow Republicans Miguel de Unamuno and José Ortega y Gasset, and ultimately from Pope Pius XI in the encyclical Dilectissima Nobis.

In recent years, the Holy See has beatified hundreds of the victims of the Red Terror (498 in one 2007 ceremony, the largest single number of beatifications in the Catholic Church's history).

[19] According to historian Ronald Radosh, "The Spanish Civil War was the culmination of long-standing tensions and social strife that no government had been able to address satisfactorily.

The result was that destitute peasants and dissatisfied workers supported either radical anarchism or socialism, buttressed by a bitter anticlericalism, while liberalism in Spain tended to be more extreme than in most of Europe.

Yet the wealthy landowners and certain areas of the country, especially the North, maintained a staunchly conservative outlook that precluded any serious reconsideration of the nation's social ills.

Many Spaniards in fact had monarchist leanings and believed that their country's salvation lay in native Spanish traditions and a strong centralized government.

Meanwhile, nationalist movements in the Basque provinces and Catalonia encouraged these people to think of themselves as distinct from the Castilians who ruled in Madrid, and as deserving of more autonomy or even outright independence from the central government... As a result, political instability prevailed throughout the nineteenth and early twentieth centuries.

Between 10 and 13 May 1931, in retaliation for left-wing demonstrators allegedly hearing a vinyl recording of the former Royalist national anthem being played through the windows of a nearby flat, more than 100 religious buildings were burned down in a wave of church arson that began in Madrid and then spread to cities and towns throughout the Second Spanish Republic.

According to the canonical narrative, Prime Minister Manuel Azaña overruled those who wished to intervene by stating, "All the convents of Spain are not worth the life of a single Republican".

[23] Among the many works of cultural heritage that were lost during the 1931 arson attacks was the copy of Marko Marulić's De institutione bene vivendi per exempla sanctorum ("Instruction on How to Lead a Virtuous Life Based on the Examples of Saints") that once belonged to St Francis Xavier.

[26] The constitution respected civil liberties and representation, but placed some restrictions on the church's use of its own property and stripped the Catholic religious orders of their previous role in the public education system.

[29] In a speech delivered on 28 November 1932, at the Madrid Ateneo, the poet Miguel de Unamuno, one of the founding fathers of the Second Spanish Republic, angrily denounced the increasingly repressive and illegal domestic policies of Prime Minister Manuel Azaña: "Even the Inquisition was limited by certain legal guarantees.

"[30] In 1933, Pope Pius XI also condemned the Spanish Republican Government's refusal to grant religious toleration to Catholics in the encyclical Dilectissima Nobis.

Lerroux's alliance with the right, his harsh suppression of the revolt in 1934 and the Straperlo and Nombela scandals combined to leave him and his party with little support going into the 1936 election.

[36] A large part of the terror consisted of a perceived revenge against bosses and clergy, as they lost their powerful position in the social revolution, and the move towards extremism that took place in the first months of the civil war.

In exchange for military aid, Stalin demanded the transformation of the Republic into a prototype for the so-called People's Democracies of Post-War Eastern and Central Europe.

"[41] The most infamous NKVD agent who served in the Republican death squads was Erich Mielke, who later became the widely detested head of East Germany's secret police, the Stasi, from 1957 through 1989.

[44] Describing specifically the Red Terror, Payne states that it "began with the murder of some of the rebels as they attempted to surrender after their revolt had failed in several of the key cities.

The victory of the centre-right in the November 1933 elections, the failed Socialist-led insurrection of October 1934 and its subsequent repression promoted a common antifascist discourse based on the dichotomy of the virtuous productive 'people' ('pueblo') (i.e. the left) and a parasitical inhuman 'fascist' enemy (i.e. the right).

When Mola's army appeared in the mountains north of Madrid, this heightened the sense of urgency within the city of the necessity of dealing with alleged fifth columns, which had been blamed for prior Republican defeats.

[73] 13 bishops were killed from the dioceses of Siguenza Lleida, Cuenca, Barbastro, Segorbe, Jaén, Ciudad Real, Almeria, Guadix, Barcelona, Teruel and the auxiliary of Tarragona.

[78] Julius Ruiz goes on to note, however, that "not cited... are El Socialista's regular reports extolling the work of the Atadell brigade", a group of Republican agents who engaged in detentions and frequently murders of (in the end) up to 800 alleged Nationalists.

Franco's victory was followed by thousands of summary executions (the remains of 35,000 people are estimated by the Association for the Recovery of Historical Memory (ARMH) to lie in mass graves)[92] and imprisonments, and many were put to forced labour, building railways, drying out swamps, digging canals (La Corchuela, the Canal of the Bajo Guadalquivir), construction of the Valle de los Caídos monument, etc.

He referred to the denunciation of his predecessor, Pope Pius XI, who had described past horrors and the need to defend and restore the rights of God and religion.

He wished peace and prosperity upon the Spanish people and appealed to them to justly punish Republicans who were guilty of war crimes, but to also exercise leniency and generosity toward the many others who were on that side.

NKVD agents sent to Spain were therefore keener on abducting and murdering anti-Stalinists among Republican leaders and International Brigade commanders than on fighting Francisco Franco.

[97] Furthermore, in a public break from his past service in the Spanish Republican Army and its Servicio de Información Militar (SIM) secret police force, Scottish Communist Hamish Fraser converted to Catholicism following World War II and expressed support for granting both diplomatic recognition and the reintegration of Spain under Franco into the international community.

[98] In later years, Fraser compared both the Red Terror and the Stalinist witch hunts among the Spanish people and within the Republican Army, in which he had been a perpetrator, with what happened throughout Eastern Europe after it was occupied by the USSR at the end of World War II.