380
The Council of Saragossa. This local Council was held in Spain It was this Council that observed Advent as a Liturgical Season.

Emperor Theodotius I makes the Catholic Faith the official Church of the Roman Empire.

St. Gregory of Nyssa, Doctor of the Church, in his sermon on St. Basil preached on St. Stephen's feast, proved that the 25th of December was already celebrated in Cappadocia, honoring the Birth of the Lord.

381
The Ecumenical Council of Constantinople I. Ecumenical means "General." This Council renewed the works of Nicea; Condemned the Macedonian heresy and declared the Holy Spirit Consubstantial with Father and Son.

382
St. Jerome translates the Bible into Latin, the Latin Vulgate Bible.

The Council of Rome. This local Council approved the Canon of the Bible. Pope Damasus writes a decree listing the Books identical to Trent's Canon.

383
St. Augustine left Carthage for Rome. He ceased being a Manichee heretic sometime the year before.

384
St. Siricius becomes Pope. He was a Roman by birth. He had been one of Pope St. Damasus I's Deacons.

Emperor Valentinian II confirmed his unanimous election. He condemned the view of Bonosus, Bishop of Naissus, that the Virgin Mary had borne children to St. Joseph after our Lord's birth, while leaving it to the Bishops of Illyricum to judge the man himself. Priscillianism, a form of the Manichaean heresy begins. It was introduced into Spain from Egypt. It was condemned at Bordeawt in the year and died out after being condemned at the Synod of Braga.

St. Jerome wrote of the doctrines of Montanism. We described them as Sabellians in their idea of the Most Holy Trinity, as forbidding second marriage, as observing three Lents, "as though three Saviors had suffered."

St. Augustine went to Milan as a teacher of rhetoric. It was there that he met St. Ambrose, who was at this time the most distinguished ecclesiastic in Italy.

385
The Nativity our Blessed Lord is celebrated on January 6th, Epiphany.

St. Ambrose in a letter to his sister uses the word Mass to describe the Eucharistic Service; it has a remained constant ever since.

386
Death of St. Gregory of Nyssa, Bishop.

387
At the Easter Vigil of the this year, St. Augustine was Baptized by St. Ambrose. St. Monica, his mother, gave thanks to God for answering her prayer.

Death of St. Monica, mother of St. Augustine at Ostia.

St. Gaudentius was consecrated by St. Ambrose. He wrote many pastoral letters during his time as bishop.

388
St. John Chrysostom preached at Rome.

The Feast honoring the Birth of Our Blessed Lord, Christmas, was set in Rome on December 25th.

389
Death of St. Gregory of Nazianzus, Bishop.

393
Synod of Hippo approved a list of Old and New Testament Books as we know them today.

397
Council of Carthage II canonized the Holy Bible.

Death of St. Ambrose.

399
Martyrdom of Pope St. Siricius.

St. Anastatsius becomes Pope. He was a married Pope. His son succeeded him to the Chair of St. Peter. He was immensely admired by St. Jerome and maintained a special relationship with the Bishop of Thessalonica.

400
The Pelagian heresy begins. These heretics denied Original Sin and rejected the necessity of Grace. Pelagius, an English monk, taught that man is born good; that he does not inherit original sin; and that he can attain supernatural life without the aid of Grace, and by his natural powers alone.