11 December - Damasus was born in 305. He lived in Rome with his family. He joined the priesthood and had a good reputation among priests. Damasus was known as a deacon of Pope Libera, who entrusted him with the position of ambassador to the emperors Valens and Valentinian.

In 355, Pope Libere, a fervent defender of the profession of Nicaea, together with St. Athanasius, was overthrown by Emperor Constance. Damasus followed Libere into exile in Thrace, and upon his death on 24th September 366, Damasus was elected to succeed him. At that time there were so-called antipapas, including Ursin. Out of jealousy, Ursin accused Damasus of adultery. He was not disturbed by these rumours, but for the good of the Church he called a synod in Rome, where he explained the situation to forty-four bishops. Ursin and his followers were excommunicated and banished from Rome.

Despite the difficulties, Damasus provided the best for the Holy See in the fourth century. In 369, on the advice of Saint Athanasius, he convened a council in Rome, condemning the decree of the false council of Rimini, which rejected the Nicene Creed and established the Auxence, an Arian, bishop of Milan. In 373, Damasus convened a second council in Rome and condemned the many heresies that threatened the Eastern Church. During this council, Pope Damasus published the Canon of Sacred Scripture, that is to say the list of books making up the Old and New Testament. He also originated the Sung Psalms and introduced the use of the "Glory to the Father, and to the Son and to the Holy Spirit" as a conclusion to the Sung Psalms. In 381, there was a second council in Aquileia to settle the dispute between the churches of Antioch. One hundred and fifty bishops of the Church of the East took part: Arius and the Macedonian king were condemned, the Orthodox faith was given a new impetus. Pope Damasus was the 37th pope, and for eighteen years he led the Universal Church. He died at the age of eighty.