VITTORI, MARIANO. - Bishop, born at Rieti in 1518, died there on 29 June 1572. Ordained a priest, he completed his studies at Siena and from there went to Rome, where, having learned Ethiopic, he published the first Institutiones grammaticali (Rome 1552).
The following year he accompanied Card. Reginaldo Polo, sent by Pope Giulio III to England in an attempt to settle the religious schism. Card. Giovanni Morone, whom V. had accompanied to the sessions of the Council of Trent, urged him to write the treatise De Sacramento confessionis, intended to combat the assertions of the Protestants. He also composed the work in four books De antiquitatibus Reatis, noteworthy, especially bk. IV, for the topography and history of the Sabine region. Finally, with acumen and learning, he edited and corrected—eliciting universal praise, including that of Card. Baronio (Martyrologium Romanum, Rome 1630, p. 485)—the works of s. Girolamo, in opposition to the edition prepared in a reforming spirit by Erasmo da Rotterdam. He was also a member of the commission of theologians and ecclesiastics entrusted with the corrections to be made to the Decree of Graziano. S. Pio V sought V. as his secretary, but he succeeded in avoiding this high office out of a desire for peace and love of his studies (autograph letter by V. Cappelletti, 15 Aug. 1572). Nevertheless, on account of his merits, he was elected by the same Pontiff to the bishopric of Amelia and subsequently appointed to that of Rieti.