Pope Damasus I was born in Rome around 305 and his parents were Antonius, who became a priest at the Church of St. Lawrence in Rome, and Laurentia. Both parents originally came from the region of Lusitania. Damasus began his ecclesiastical career as a deacon in his father's church, where he went on to serve as a priest.

When Pope Liberius was banished by Emperor Constantius II to Berea in 354, Damasus was archdeacon of the Roman church and he followed Liberius into exile, though he immediately returned to Rome. During the period before Liberius' return, Damasus had a great share in the government of the church.

Following the death of Pope Liberius on 24 September 366, Damasus succeeded to the Papacy.

Pope Damasus I was active in defending the Catholic Church against the threat of schisms. In two Roman synods (368 and 369) he condemned Apollinarianism and Macedonianism, and sent legates to the First Council of Constantinople that was convoked in 381 to address these heresies.

One of the important works of Pope Damasus was to preside in the Council of Rome of 382 that helped determine the canon or official list of Sacred Scripture. The council gave a complete list of the canonical books of both the Old Testament and the New Testament which is identical with the list given at Trent.

In order to put an end to the marked divergences in the western texts of that period, Pope Damasus encouraged the highly respected scholar Jerome to revise the available Old Latin versions of the Bible into a more accurate Latin on the basis of the Greek New Testament and the Septuagint, resulting in the Vulgate. According to Protestant biblical scholar, F.F. Bruce, the commissioning of the Vulgate was a key moment in fixing the biblical canon in the West.

Pope Damasus also did much to encourage the veneration of the Christian martyrs, restoring and creating access to their tombs in the Catacombs of Rome and elsewhere, and setting up tablets with verse inscriptions composed by himself, several of which survive or are recorded in his Epigrammata.

Pope Damasus reigned for eighteen years and two months. He died on 11 December, 384 and was buried beside his mother and sister in a "funerary basilica ... somewhere between the Via Appia and Via Ardeatina".

Other Saints of the Day
1. Saint Acepsius
2. Saint Barsabas
3. Saint Daniel the Stylite
4. Saint Fidweten
5. Saint Sabinus