5 It is scarcely necessary, Venerable Brothers, to go back very far in order to narrate the sad calamities which have fallen upon the Church of Mexico. It is sufficient to recall that the frequent revolutions of modern times have ended in the majority of cases in trials for the Church and persecutions of religion. Both in 1914 and in 1915 men who seemed veritably inspired by the barbarism of former days persecuted the clergy, both secular and regular, and the sisters. They rose up against holy places and every object used in divine worship and so ferocious were they that no injury, no ignominy, no violence was too great to satisfy their persecuting mania.
Source: Iniquis Afflictisque (Vatican.va)