Norman P. Tanner, SJ is a Catholic historian and priest of the Jesuit Order. He currently holds the position of Professor of Church History at the Pontificia Universita Gregoriana, in the Vatican City, Rome. Fr. Tanner entered the Jesuit Order in 1961, and achieved his S.T.L. in Church history under the renowned historian, Frederick Copleston, SJ. He then received his Ph.D at Oxford University, as a member of Campion Hall; he also holds a B.Theol from the Gregorian University. An internationally-acclaimed expert in Church councils, Fr. Tanner is the editor of a definitive translation of the major documents of the councils: Decrees of the Ecumenical Councils (2 vols). He has a special love for the later Middle-Ages, and has written several books on popular religion in the Medieval period, as well as a plethora of books and articles on the history and practice of the historical Church councils. Fr. Tanner taught from 1978 until 2003 at Oxford University (a University Research Lecturer from 1997 until 2003); leaving his post to take up his current place at the Gregorian University.