The Assumption of Mary is one of the four Marian dogmas of the Catholic Church. Pope Pius XII defined it on 1 November 1950 in his apostolic constitution Munificentissimus Deus as the assumption of Mary, body and soul, into heaven. From Wikipedia
At Villa Barberini he has halted formal audiences, maintained Mass and Angelus services, scheduled his return after the Feast of the Assumption.
