Natalis Invicti
The well-known solar feast, however, of Natalis Invicti, celebrated on 25 December, has a strong claim on the responsibility for our December date. For the history of the solar cult, its position in the Roman Empire, and
syncretism with
Mithraism, see Cumont's epoch-making "Textes et Monuments" etc., I, ii, 4, 6, p. 355. Mommsen (Corpus Inscriptionum Latinarum, 1[SUP]2[/SUP], p. 338) has collected the evidence for the feast, which reached its climax of popularity under
Aurelian in 274. Filippo del Torre in 1700 first saw its importance; it is marked, as has been said, without addition in Philocalus' Calendar. It would be impossible here even to outline the history of solar symbolism and language as applied to
God, the
Messiah, and
Christ in Jewish or Christian canonical, patristic, or devotional works. Hymns and Christmas offices abound in instances; the texts are well arranged by Cumont (op. cit., addit. Note C, p. 355).