As its name suggests, the Epiphany had its origin in the Eastern Church. The first reference about which we can feel certain is by St. Clement of Alexandria (Stromata I.21.45), who writes: “There are those, too, who over-curiously assign to the Birth of Our Saviour not only its year but its day, which they say to be on 25 Pachon (20 May) in the twenty-eighth year of Augustus. But the followers of Basilides celebrate the day of His Baptism too, spending the previous night in readings. And they say that it was the 15th of the month Tybi of the 15th year of Tiberius Caesar. And some say that it was observed the 11th of the same month.” Now, 11 and 15 Tybi are 6 and 10 January, respectively.
The brings up the question; did these Basilidians celebrate Christ’s Nativity and also His Baptism on 6 and 10 January, or did they merely keep His Baptism on these days, as well as His Nativity on another date? The evidence, if not St. Clement’s actual words, suggests the former.
Moreover, Epiphanius says that the sixth of January is Christ’s Birthday, i.e. His Epiphany. However, he assigns the Baptism to 12 Athyr, i.e. 6 November and he asserts that Christ’s Birth, i.e. Theophany, occurred on 6 January, as did the miracle at Cana.
Now, owing no doubt to the vagueness of the name Epiphany, very different manifestations of Christ’s glory and Divinity were celebrated in this feast quite early in its history, especially the Baptism, the miracle at Cana, the Nativity, and the visit of the Magi. But we cannot for a moment suppose that in the first instance a festival of manifestations in general was established, into which popular local devotion read specified meaning as circumstances dictated.
It seems fairly clear that the Baptism was the event predominantly commemorated on January 6th, as it remains in the Eastern Catholic Churches today (The Apostolic Constitutions mention it). Kellner quotes the oldest Coptic Calendar for the name Dies baptismi sanctificati, and the later for that of Immersio Domini as applied to this feast.
St. Gregory of Nazianzus probably preached on the 25 Dec., 380; and after referring to Christ’s Birth, he assures his hearers that they shall shortly see Christ baptized. On 6 and 7 Jan., he preached orations and declared that the Birth of Christ and the leading of the Magi by a star having been already celebrated, the commemoration of His Baptism would now take place. The first of these two sermons is headed eis ta hagia phota, referring to the lights carried on that day to symbolize the spiritual illumination of baptism.
SIDENOTE: St. Chrysostom, however, in 386 calls the Nativity the parent of festivals, for, had not Christ been born, neither would He have been baptized.
In the present Office, the Magnificat antiphon of Second Vespers reads: “We keep our Holy Day adored with three miracles: today a star led the Magi to the crib, today wine was made from water at the marriage, today in Jordan Christ willed to be baptized by John to save us.”
On this day, January 6th, it is common for the Western Churches to take on the celebration of the Magi. In the Eastern Churches, it is more common to celebrate the baptism in the Jordan (also know as Theophany).