Damasus, by birth a Spaniard, governed the Church from 366 to 384. “The ancients,” according to Alban Butler, “particularly commend his constancy in maintaining the purity of our holy faith, the innocence of his manners, his Christian humility, his compassion for the poor, his piety in adoring holy places, especially the tombs of the martyrs, and his singular learning.” Much of our knowledge about the martyrs is derived from the inscriptions, which he composed in their praise. He established rules for the liturgical singing of the Psalms and decreed that the Gloria Patri should be said at the end of each Psalm. At his command St. Jerome translated the New Testament into Latin. This Pope also confirmed the second ecumenical council, held at Constantinople.
(Source: The New Roman Missal, Rev. F. X. Lasance)