4 In the midst of these oppressive conditions, which so torment a beloved part of the Christian flock, We recall with pleasure the day, now many years ago, when We journeyed to Budapest to take part in an international Eucharistic Congress as personal representative of Our Predecessor of happy memory, Pius XI. We then had the joy and consolation of seeing the dear Catholics of Hungary follow with ardent piety and profoundest veneration the August Sacrament of the altar as it was carried in solemn procession through the streets of the city.
Source: Luctuosissimi Eventus (Vatican.va)