What is World Day of Migrants?

Yesterday was the World Day of Migrants and Refugees, a commemoration instituted by St. Pius X. Pope Francis’s message for the day, written on May 3, is entitled “Towards an Ever Wider ‘We.’” Venerable Pius XII’s 1952 apostolic constitution “The émigré Holy Family of Nazareth,” is sometimes referred to as the Magna Carta of Catholic teaching on migration.