3 More than this; Rome, the most august of Christian cities, is now a place laid open to all the enemies of the Church; profane novelties defile it; here and there, temples and schools devoted to heresy are to be found. It is even reported that this year it is about to receive the deputies and leaders of the sect which is most embittered against Catholicism, who have appointed this city as the place for their solemn meeting. The reasons which have determined their choice of such a meeting place are no secret; they desire by this outrageous provocation to glut the hatred which they nourish against the Church, and to bring their incendiary torches within reach of the Roman Pontificate by attacking it in its very seat.
Source: Etsi Nos (Vatican.va)