In this article, Michael A. Blume, SVD, Undersecretary for the Vatican's Pontifical Council for the Pastoral Care of Migrants and Itinerant People, presents a valuable introduction to the issues involved in the pastoral care of "uprooted peoples." Fr. Blume addresses the complex questions of "who is a refugee?" and "how many refugees are there?" and concludes the article with reflections on the future of the world's refugees and the connection between the pastoral care of refugees and the mission of the church.