Yalda / Khor-Ruz / a Legacy of Ancient Iranshahr — Continued (3)

This day also stands in relative proximity to the celebration of the birth of Jesus Christ on 25 December among Christians around the world. The source argues that, according to its reading of the Gospel of Luke, Jesus was born not in winter and December but in summer.

It states that, according to the Jewish religious calendar, the month in which Gabriel appeared to Mary was the final month of summer and therefore Christ’s birth should have taken place at the beginning of the following summer. The source further points to Luke’s account of Christ’s birth during the season when sheep were grazing, adding that shepherds would not take sheep out to pasture in winter, and notes the absence of other signs of winter in the birth narrative.

The question, then, is why 25 December was chosen as the date of Christ’s birth.

The text connects this question to the spread of Mithraism in Rome and to the popularity of “Sun Day” and the belief in darkness being defeated on this night, a day regarded as the birthday of Mithra.

It further states that the calendar used by the Romans was Greek and attributes the movement of the date from 21 to 25 December to a calendrical miscalculation, a possibility it says many historians have emphasized.

Have we ever asked why the sacred weekly holiday among Christians is called Sunday—a combination of Sun and Day?

Is it merely accidental that both Mithraism and Christianity called their sacred day of the week Sun Day? (In the Mithraic tradition, the final day of the week is described here as Mehr-Shid, the day of the sun.)
The source notes that Constantine, the first Roman emperor to do so, made this day a holiday in 321 CE under the name Day of the Sun. It attributes this to the spread of Mithraism in Rome and the sacred status of the day among Roman people and soldiers, suggesting that the most effective way to spread Christianity rapidly was to use existing traditions and change their meaning.

The text describes 21 December, or Yalda Night, as one of the greatest national festivals in the Roman Empire before the adoption of Christianity, celebrated under the name Divalia in honour of the “returning sun.”

In recent years, the remains of Mithraic temples and sanctuaries have been found not only across Asia Minor and the Iranian plateau but extensively throughout Europe, from Italy to Germany, Ireland, and England. Images preserved in these temples have contributed to new information about Mithra, this mysterious figure of history.

The source interprets this evidence as indicating a figure distinct from the ancient Iranian deity: Mithra as saviour and Iranian prophet, representing a highly organized yet esoteric religion. It describes a prophet who appears under the signs of Mithra and his return, and argues that dozens of images, statues, and surviving temples reveal the distinctive spread of this religion shortly before the birth of Christ, especially in the Roman Empire. It further argues that today the Catholic Church, and consequently many institutions even in Western universities, seek to pass over this religion by subsuming it under the broad label of paganism, polytheism, or heresy.

There is much to say about the relationship between Catholic Church traditions and Mithraic practices, especially those connected with New Year celebrations—Christmas—and that discussion is deferred to a later point. One important detail noted here is that 17–25 December are celebrated in Christian traditions as the final week before Christ’s birth, with each day carrying a particular name, songs, and prayers. The especially interesting point, in the source’s argument, is that 21 December—the birthday of the solar deity Mithra in ancient Indo-European traditions—is known in these devotional antiphons as Oriens, or the rising sun. The Latin word oriens also means east, the point from which the sun, or Mithra, appears and is born.