Wrong. Saint Gregory of Nazianza started the Nativity Feast at Constantinople. That is what the Eastern Churches of the Byzantine tradition use.
In 379 or 380 Gregory Nazianzen made himself exarchos of the new feast, i.e. its initiator, in Constantinople, where, since the death of Valens, orthodoxy was reviving. His three Homilies (see Hom. xxxviii in P.G., XXXVI) were preached on successive days (Usener, op. cit., p. 253) in the private chapel called Anastasia. On his exile in 381, the feast disappeared.
According, however, to John of Nikiû, Honorius, when he was present on a visit, arranged with Arcadius for the observation of the feast on the Roman date. Kellner puts this visit in 395; Baumstark (Oriens Chr., 1902, 441-446), between 398 and 402. The latter relies on a letter of Jacob of Edessa quoted by George of Beeltân, asserting that Christmas was brought to Constantinople by Arcadius and Chrysostom from Italy, where, “according to the histories”, it had been kept from Apostolic times. Chrysostom’s episcopate lasted from 398 to 402; the feast would therefore have been introduced between these dates by Chrysostom bishop, as at Antioch by Chrysostom priest. But Lübeck (Hist. Jahrbuch., XXVIII, I, 1907, pp. 109-118) proves Baumstark’s evidence invalid. More important, but scarcely better accredited, is Erbes’ contention (Zeitschrift f. Kirchengesch., XXVI, 1905, 20-31) that the feast was brought in by Constantine as early as 330-35.
In Antioch, on the feast of St. Philogonius, Chrysostom preached an important sermon. The year was almost certainly 386, though Clinton gives 387, and Usener, by a long rearrangement of the saint’s sermons, 388 (Religionsgeschichtl. Untersuch., pp. 227-240). But between February, 386, when Flavian ordained Chrysostom priest, and December is ample time for the preaching of all the sermons under discussion. (See Kellner, Heortologie, Freiburg, 1906, p. 97, n. 3). In view of a reaction to certain Jewish rites and feasts, Chrysostom tries to unite Antioch in celebrating Christ’s birth on 25 December, part of the community having already kept it on that day for at least ten years. In the West, he says, the feast was thus kept, anothen; its introduction into Antioch he had always sought, conservatives always resisted. This time he was successful; in a crowded church he defended the new custom. It was no novelty; from Thrace to Cadiz this feast was observed – rightly, since its miraculously rapid diffusion proved its genuineness. Besides, Zachary, who, as high-priest, entered the Temple on the Day of Atonement, received therefore announcement of John’s conception in September; six months later Christ was conceived, i.e. in March, and born accordingly in December.
Finally, though never at Rome, on authority he knows that the census papers of the Holy Family are still there. [This appeal to Roman archives is as old as Justin Martyr (Apol., I, 34, 35) and Tertullian (Adv. Marc., IV, 7, 19). Julius, in the Cyriline forgeries, is said to have calculated the date from Josephus, on the same unwarranted assumptions about Zachary as did Chrysostom.] Rome, therefore, has observed 25 December long enough to allow of Chrysostom speaking at least in 388 as above (P.G., XLVIII, 752, XLIX, 351).
I’m sure Saint Gregory had no idea of what the Gallicans used or did.
Why? The Paschal controversy of the second century, during the persecusions, and later, show the Church was very aware of what the individual Churches were doing.
And from this period we know, for instance, St. Hillary of Poitiers went to Constantinople. And the emperors in Constantinople were heavily involved in Gaul (e.g. Julian became emperor in Paris).
The preporatory period is not Latin.
The preporatory period doesn’t date from the 4th century, but later. It’s fuller development was the gift of the Gallic Church to the Church as a whole.
