Giuseppe Marchi (22 February 1795, Tolmezzo – 10 February 1860, Rome) was an Italian Jesuit archæologist who worked on the Catacombs of Rome. Life He entered the Society of Jesus in Rome 12 November 1814, shortly after the re-establishment of the order, and was professor of humanities successively in the colleges of Terni, Reggio Emilia, Modena and St. Andrew of the Quirinal. After completing his course and making his religious profession (1833) he became professor of rhetoric in the Roman College and held this position until 1842. Meanwhile, he devoted his leisure to study, applying himself through choice to non-Christian antiquities. He soon gave special attention to Christian antiquities, hoping thus to find a means of restoring Christian art. In 1838 he was made prefect of the Kircherian Museum, a position he retained until his death. Marchi attempted a reorganization of the collection and produced a monograph on the ancient coins preserved there, the Aes grave del Museo Kircheriano. In 1840 he announced his intention of collecting into one large publication the monuments of Christian architecture, painting, and sculpture. His archæological pursuits recommended him to Gregory XVI as qualified to succeed Settele in the position of Conservatore dei sacri cimiteni di Roma (1842), charged with supervising the early Christian burial places in and around the city. He brought to the study of early Christian monuments a new scholarly rigor. About this time Marchi made the acquaintance of youthful Giovanni Battista De Rossi, who accepted him as master and thenceforth accompanied him on his visits to the Roman catacombs. Art historian Raffaele Garrucci was also one of Marchi's associates. These ancient cemeteries had been abandoned but thereafter were more accessible and could be studied on the ground. In spring 1842, Marchi conducted a tour of the Catacombs of Saint Agnes for James Roosevelt Bayley, John Bede Polding, and a number of people from the English College, Rome. In 1844 Marchi published the first volume of his "Monumenti", devoted to the construction of the catacombs, especially that of Saint Agnes. He proved the Christian origin of these ancient burial-places and, through his studies, brought about (21 March 1845) the discovery of the crypts of Saints Peter and Hyacinth in the catacomb of St. Hermes. It was De Rossi who made the great discoveries in the catacombs. He knew better than Marchi how to make use of ancient topographical data and all the