Find accurate definitions of over 5,000 Catholic terms and phrases (including abbreviations). Based on Fr. John Hardon's Modern Catholic Dictionary, © Eternal Life. Used with permission.
That part of Rome situated on the right bank of the Tiber, so called in honor of Pope St. Leo IV, who between 848 and 852 surrounded it with a wall when the Moslems were threatening the city. It contains the Basilica of St. Peter and the Vatican.