Short answers, pulled from the story.
Anti-clericalism is opposition to religious authority, particularly in social and political matters. Historically, it has most often targeted the influence of the Catholic Church and its clergy in secular governance, education, property rights, and civil life.
During the Spanish Civil War of 1936-1939, anti-clerical assaults called the Red Terror by Nationalists killed 6,832 members of the clergy. This included 13 bishops, 4,172 diocesan priests, 2,364 monks and friars, and 283 nuns.
The Cristero War was an armed peasant rebellion from 1927 to 1929, supported by the Catholic Church, against the Mexican government's anti-clerical laws. The conflict was triggered by laws including the Calles Law, which enforced constitutional provisions banning public worship, suppressing religious orders, and stripping clergy of political rights. By 1934, only 334 priests were licensed to serve fifteen million people, down from 4,500 before the rebellion.
The French revolutionary government passed the Civil Constitution of the Clergy on the 12th of July 1790, requiring all clerics to swear allegiance to the state. During the Reign of Terror, the authorities nationalized church property, exiled 30,000 priests, killed hundreds more, and replaced the Christian calendar with one reckoning from the date of the Revolution. Many churches were converted into temples of reason for new civic ceremonies.
The Kulturkampf was a campaign by Prussian Prime Minister Otto von Bismarck from 1871 to 1878 to reduce the Catholic Church's role in Prussia. At its height, half of the Prussian bishops were in prison or exile, 1,800 parish priests were imprisoned or exiled, and a third of monasteries and convents were closed. The campaign backfired by galvanizing Catholics into an organized political force in the Centre party and reviving Polish resistance, leading Bismarck to wind it down around 1880.
In French Canada, a small anti-clerical Liberal movement emerged in the early 19th century, eventually forming the Parti rouge in 1848 and merging with English Reformers by 1861. After Wilfrid Laurier led the Liberals away from anti-clericalism, the party dominated much of the 20th century. The decisive break came during Quebec's Quiet Revolution in the 1960s, when the provincial government took over health and education from the church, making Quebec Canada's most secular province.