In my prior post inaugurating my personal War on Christmas in my own fair and balanced way, I showed that there was no historical memory that Jesus was born on December 25. We really cannot say that any particular day was his birthday given our sources. However, we still have to wonder how did the various traditional dates come about?
Besides tradition, the most common argument was that the birth of Jesus corresponded with the date of the birth of Sol Invictus, though often people will say Mithras. The connection is fairly straight-forward: the celebration of Sol Invictus takes place on the winter solstice when the sun in lowest in the sky and the days are shortest, but then the days get longer and the sun higher. In essence, the sun is “born again”, and this was the birth of Sol. The cult with this god was popular, and the burgeoning Christian cult in the 4th century tried to co-opt the holiday in order to make conversion easier. Emperor Constantine is also part of the mix in most investigations. As such, at its roots Christmas is a very pagan holiday.
That’s the basic outline version of what most think is the origin of the Dec 25 birthday tradition for Jesus. Along the way there will be confusions of mixing in the celebrations of Saturnalia, a festival that was about a week long and ended on Dec 23, not the 25th. There are similarities with the festival of Saturn and the festival of Christ’s birth, but they do not overlap in time.
But ignoring this minor side-error, can we pin down this connection between the alleged date of Jesus’ birth and that of Sol Invictus? Was Mithras’ day of birth celebrated on the winter solstice? Can we see the order of operations and determine who influenced who and when? And can I have a Official Red Ryder Carbine-Action Two-Hundred-Shot Range Model Air Rifle?
Let’s start by taking a look at when Mithras is said to have been born. What is actually surprising is what isn’t said in our sources: there is no evidence before the 4th century of any such belief that Mithras was born on Dec 25th. In actual fact, we have almost nothing to go on for the celebrated birth date of Mithras as all, though some speculate the autumnal equinox (1). The earliest solid evidence relating Dec 25 and the Sol Invictus cult comes from the Calendar of Filocalus, a.k.a. the Calendar of 354. But this is the same early source for showing that Jesus was born on Dec 25. From this alone we cannot say which tradition is older, let alone who influenced whom.
But there is more that makes things dicier. The calendar says on Dec 25 the following: N. INVICTI C.M. XXX ; that abbreviated phrasing means natalis [Solis] Invicti; c(ircenses) m(issus) XXX. The word that deserve attention is natalis which can definitely mean ‘birthday’. However, it also can have a technical meaning for the date of the dedication of a temple or a festival day (2). The Dec 25 event may just be the dedication of a temple and have nothing to do with the birth of a god. We also are uncertain when the temple dedication was. Scholars have suggested it happening under Emperor Aurelian (c. 274 CE), but we have no strong reasons to think that; others suggest more plausibly that Aurelian had celebrations in late October for Sol (3). We also have to realize that when the text of the calendar mentions Invici, it doesn’t necessarily include Sol/Mithras, which means we have to speculate that even in 354 there was a Dec 25 Sol festival.
On the other hand, when did some Christians begin to think Jesus was a Dec 25th baby? There is actually some indication that it began before Constantine hit the big time. We learn from Augustine of Hippo about a group known as the Donatists that formed during the reign of Diocletian, the last emperor that really persecuted Christians. The Donatists were supposed to be steadfast in their traditions, and Augustine (Sermon 202) said they would not commemorate the Epiphany with the Eastern Church on Jan 6 but instead stuck with their Dec 25 commemoration. Since the Donatists formed during the persecutions, and supposing they did actually hold to Dec 25 date of Jesus’ birth, then we have evidence there were at least some Christians believing in a winter solstice date for Christ’s birth nearly a half-century before the earliest attestation of the Sol Invictus festival on the same day.
So, from what we can tell, there is some evidence that puts the celebration of Jesus’ birth on Dec 25 before any evidence of a festival about Sol Invictus on the same day. As such, we do not have a good argument to say that the Christians adopted a pagan festival for their own in this particular case.
So how did we actually get Dec 25? What about other dates for Christmas, such as Jan 6? This will be explored next time, and it is very interesting.
(1) Jaime Alvar, Romanising Oriental Gods, p. 100.
(2) Michele Salzman, On Roman Time, esp. p. 119; Alvar, op. cit., p. 411.
(3) Steven Hijmans, Sol : the sun in the art and religions of Rome (2009).