Father Ennis was the first director of the Augustinian Historical Institute of Villanova University. Through his efforts the Augustinian Historical Institute, founded at Riverdale, New York City, by Reverend Francis Roth, O.S.A., of the Canadian Province, was relocated at Villanova University and inaugurated on April 6, 1973.
Arthur Ennis was born on October 22, 1922, in Brooklyn, New York. He was professed in the Order of St. Augustine on September 10, 1941. After graduation from Villanova University in 1945, he studied at Augustinian College in Washington, D.C., where he was ordained to the priesthood on February 10, 1949. Having receiving the degree of Master in Medieval History at Catholic University in Washington, D.C., he completed studies for a doctorate in Church History at the Gregorian University in Rome in 1953.
Father Ennis served in many significant positions in the Order of St. Augustine both in this country and in Rome. Besides the offices of director of students, local superior of several communities, and province counselor, he was assistant general for the North American provinces of the Augustinian Order from 1977-1983. His academic career included professorships at Augustinian College in Washington and Villanova University, where he served a term as Chair of the Department of Religious Studies.
Bibliography of Arthur J. Ennis O.S.A.
- A Translation and Introductory Study of the "Tractatus de origine et progressu ordinis fratrum eremitarum S. Augustini et vero ac proprio titulo eiusdem," by Henry of Friemar, O.S.A. M.A.dissertation, Catholic University of America 1949.
- Fray Alonso de la Vera Cruz, O.S.A., 1507-1584: A Study of His Life and His Contribution to the Religious and Intellectual Affairs of Early Mexico. Louvain: Impr. E. Warny, 1957. Offprint from Augustiniana, 5-7 (1955-57). This work was based on his doctoral dissertation at the Gregorian University in Rome.
- Old St. Augustine's Catholic Church in Philadelphia: Historic Shrine Established in A.D. 1796. Philadelphia: n.p., 1965.
- The Augustinians: A Brief Sketch of Their American History from 1796 to the Present. Villanova, PA: Augustinian Press, 1985.
- Augustinian Religious Professions in Sixteenth Century Mexico: A Study of the Earliest Records of Augustinian Friars Professed in the New World. Villanova, PA: Augustinian Historical Institute, Villanova University, 1986.
- No Easy Road: The Early Years of the Augustinians in the United States, 1796-1874. New York: Peter Lang, 1993.
- A History of the Augustinian Order, by Balbino Rano Gundin. Rome: privately printed, 1975.
- The Augustinians in the Middle Ages, 1256-1356, by David Gutiérrez, O.S.A. Villanova, PA, Augustinian Historical Institute, 1984.
Articles on the History of the Church and the Augustinian Order
- "The Rule of Saint Augustine: Its True History." The Tagastan 9 (1946), 81-91.
- "Augustinian College." The Tagastan 10 (1946), 5-10.
- "Our Lady of Good Counsel: Mother of the Catholic Action." The Tagastan 11 (1947), 26-31.
- "The Contribution Made to Humanistic Studies in Early Mexico by Fray Alonso de la Vera Cruz, O.S.A. (1507-1584)." Analecta Gregoriana 70 (1954), 307-27.
- "An Unpublished Manuscript Containing Statistics and Biographical Notes concerning the Augustinians in Mexico c. 1595." Augustiniana 6 (1956), 630-34.
- "The Historical Development of the Constitutions of the Order as Seen Chiefly through an Analysis of the Ratisbon Text 1290." In Second Annual Course on Augustinian Spirituality, Rome: [Order of St. Augustine], 1976, 133-46.
- "The Spirit of the Present Constitutions: An Attempt to Recapture the Elements of Our Original Charism." In Second Annual Course on Augustinian Spirituality, Rome: [Order of St. Augustine], 1976, 146-55.
- "The New Diocese of Philadelphia." In The History of the Archdiocese of Philadelphia, ed. James F. Connelly, Philadelphia: The Archdiocese of Philadelphia, 1976, 63-112.
- "The Villanova Province Archive." Analecta Augustiniana 39 (1976), 369-72.
- "The Founding of the Augustinians in the United States (1796)" With an Appendix of Documents. Analecta Augustiniana 41 (1978), 285-312.
- "The Augustinians in the United States: The Story of Matthew Carr, O.S.A. (1755-1820)." The Tagastan 29 (1983), 7-38, 177-196; 30, (1984), 75-112, 131-159.
- "Matthew Carr, 1755-1820." In Men of Heart, ed. John Rotelle, O.S.A., Villanova PA: Augustinian Press, 1983, 1: 9-25.
- "John Rosseter, 1751-1812." In Men of Heart, ed. John Rotelle, O.S.A., Villanova PA: Augustinian Press, 1986, 2: 7-14.
- "Patrick A. Stanton, 1826-1891." In Men of Heart, ed. John Rotelle, O.S.A., Villanova PA: Augustinian Press, 1986, 2: 93-107.
- "Amédée J. Viger, 1876-1915." In Men of Heart, ed. John Rotelle, O.S.A., Villanova PA: Augustinian Press, 1986, 2: 109-114.
- "The Augustinians of Mombassa." Augustinian Heritage, 32 (1986), 247-54.
- "The Augustinians in the United States: The Story of Michael Hurley, O.S.A. (1780-1837)." Augustinian Heritage 34 (1988), 119-148.
- "The Historical Development of the Augustinian Constitutions: The Ratisbon Text of 1290." Augustinian Heritage 36 (1990), 45-57.
- "The Augustinians in the United States: The Story of Patrick Eugene Moriarty, O.S.A. (1805-1875)." Augustinian Heritage 39 (1991), 67-88.
- "Andres de Urdaneta, O.S.A., Discoverer of the Route of the Manila Galleon." Augustinian Heritage 38 (1992), 109-114.
- "The Hermit Tradition: Its Origen and Influence in Augustinian History." Augustinian Heritage 39 (1993), 131-61.
Articles in the New Catholic Encyclopedia 1967 Edition
- "Adrian II, pope." "Adrian III, pope, saint." "Amalric Augerius." "Anastasius III, pope." "André, Bernard (Andreas). "Augustine Novellus, Bl." "Augustinian Spirituality." "Basalenque, Diego." "Boniface VI, pope." "Bridgettines." "Calancha, Antonio de la." "Carr, Thomas Matthew." "Christian Doctrine (Nancy), Sisters of." "Dominicans—Sisters: Poor School Sisters of Penance." "Galberry, Thomas." "Grijalva, Juan de." "Jones, William Ambrose." "Little Sisters of the Holy Family." "Little Sisters of the Poor and Aged." "Missionary Sisters of Notre Dame des Anges." "Moriarty, Patrick Eugene." "Noris, Henry." "Oblate Sisters of the Most Holy Redeemer." "Our Lady of Good Counsel." "Padilla, Diego Francisco." "Religious Orders of Men in Latin America: Spanish America, Augustinians." "Sisters of Charity of Zams, Austria." "Ste. Chrétienne, Sisters of." "Vásquez, Francisco Javier." "Villarroel, Gaspar de." "Vincentian Sisters of Charity of Bedford, Ohio." "Zapata y Sandoval, Juan."
In addition, Father Ennis published at least 15 book reviews in various journals.