CASANATE, GIROLAMO. - Dominican cardinal, b. in Naples on 13 Feb. 1620 to an ancient and noble Spanish family, d. in Rome on 3 March 1700.
In 1635 he took his degree in utroque iure at the University of Naples. Having taken the Dominican habit, in 1645 he went to Rome, where Innocent X, who as cardinal had taken a liking to him, appointed him chamberlain of honor; afterward C. entered the prelature and became an assistant at the Roman court. In 1648 he was elected governor of Sabina, where he remained four years, winning esteem for his intelligent administration.
In 1652 governor of Fabriano, in 1656 governor of Ancona; at the beginning of Jan. 1658 the cardinal secretary of State summoned him again to Rome. He remained for some months free of offices, so that he could devote himself to his favorite studies among the numerous books he had already collected. On 23 Sept. he left Rome to go and assume the post of inquisitor of Malta. He returned to Rome on 7 June 1663, and in the decade 1663-73 he was assigned to various high offices, among them that of governor of Borgo (1665-1667), of governor of the Conclave (2 June 1667), of assesssor of the Holy Office for more than five years, and secretary of the Congregation of Bishops and Regulars, until on 6 June 1673 Clement X created him cardinal of the title of St. Mary in Portico. He was assigned five of the most important Congregations, among them that of the Holy Office. In 1693 Innocent XII appointed him librarian of the Holy Roman Church, and in this dignity his fame as a patron of the arts was consolidated. Eager to publish the ancient unpublished works of the Vatican Library, he entrusted to the vice-librarian Abbot Zaccagni a series of volumes entitled Collectanea monumentorum veterum Ecclesiae graecae et latinae, which, however, was suspended after the first volume because of Casanate's death. In the political field, Casanate's work during the conflict between the Holy See and Louis XIV was notable, and it is chiefly due to him that Innocent XI firmly upheld the rights of the Church, so that Casanate earned the hatred of the King of France, who in the subsequent conclaves up to 1700 sent his veto against him, while nonetheless admiring his learning and his intellect. He played a large part in the condemnation of Miguel Molinos and in having the doctrines of the Quietists declared heretical by a bull whose draft he himself wrote (1687).
Casanate is one of the greatest ecclesiastical personalities of the seventeenth century; his figure as a scholar is of particular importance: a collector of books and a researcher of ancient documents, he had assembled a library rich in more than 25,000 volumes, among them many valuable manuscripts, which he bequeathed to the Dominicans of the Minerva, adding to it the sum of 160,000 Roman scudi for the founding of a great public library next to the convent (bibliotheca Casanatensis). He assigned other revenues for the founding of a college of Dominican theologians (theologi casanatenses) for the study of theology and two chairs for the teaching of the Summa of St. Thomas.