Christian archaeologist, born Rome, Italy, 1822; died Castel Gandolfo, 1894. Graduated in law at the Sapienza, he was appointed a scriptor at the Vatican Library. From childhood he had shown interest in antiquities, and in 1841 he began the study of archaeology under the Jesuit, Marchi. As a result of his explorations and researches De Rossi became a famous authority on epigraphy and Roman topography, and stirred up a world-wide interest in Christian antiquities. In addition to more than two hundred archaeological and historical monographs he wrote several comprehensive works on the catacombs, and early Christian Roman inscriptions, the most important being "La Roma sotterranea cristiana". Elevated Christian archaeology to the dignity of a science. He was commissioned by Pope Pius IX to systematically investigate the catacombs on scientific principles; his immense learning and careful observations were shown by his voluminous literary output. His Roma Sotterranea Cristiana (Rome, 1864) is almost indispensable to the student of Christian archaeology, as is his periodical Bulletino d'archeologia cristiana, a publication begun in 1863 and ended in 1894.