This short post is about a very special day of the year, 25 December. On this day, Christians and non-Christians alike celebrate Christmas everywhere in the world. On the internet, you will often find the claim that the date of 25 December derives from the ancient cult of Mithras, which was once very popular in the Roman Empire. So is this claim correct? The simple answer is ‘no’.
Winter solstice and Sol Invictus
In the Roman world, 25 December was traditionally the date for the winter solstice, the shortest day of the year. In his Historia Naturalis, the Roman author Plinius the Elder explains that this solstice – bruma in Latin – begins on the eighth day before the kalendae of the month of January. The kalendae or calends was the first day of the month. Going back eight days from the first of January – a day which is included in the Roman way of counting – we get to 25 December. The Romans were a people of farmers, and for them the seasons and phenomena such as the winter and summer solstice and the equinox were of major importance. It should be noted that Plinius wrote his comment on the winter solstice in the eighteenth book of his Historia Naturalis, which is about agriculture. There may or may not have been a link between the winter solstice and the celebration of the Roman festival of the Saturnalia, which was held from 17 until 23 December. Saturnus was an ancient Italian god of agriculture.
We can safely conclude that the date of 25 December was traditionally important in the Roman world. There is also a strong link between this date and the cult of Sol Invictus, the Unconquered Sun. According to tradition, this solar deity was born on 25 December. The large temple of Sol Invictus in Rome, commissioned by the emperor Aurelianus (270-275), was inaugurated on 25 December 274. By that time, the Romans already had a long history of sun god worshipping. The emperor Vespasianus (69-79) for instance converted the Colossus of Nero, which stood in front of the Colosseum, into a statue of the sun god Sol, who in turn seems to have been copied from the Greek sun god Helios.
In the third century, the cult of the sun god was given a boost when emperors from the so-called Severan dynasty took control of the Empire. The emperor Septimius Severus (193-211), who was himself from Leptis Magna in Africa, was married to a Syrian woman, whose father was a high priest of the sun god Elagabal (‘god of the mountain’). The temple of Elagabal was located in Emesa, Syria (present-day Homs), where the deity was worshipped in the form of a large black rock, which according to tradition had fallen from heaven. The cult of Elagabal was introduced in Rome by the emperor Elagabalus (218-222), who was himself a high priest as well. According to our sources, the emperor tried to impose his religion upon the Romans, who responded with hostility and anger. When the hated emperor was murdered, the cult of Elagabal soon came to an end (the ruins of his temple in Rome can still be seen on the Palatine Hill, see here). However, the practice of worshipping the (or: a) sun god continued or perhaps it was reintroduced by the aforementioned Aurelianus. To be honest, we do not really know the precise relationship between Sol, Elagabal and Sol Invictus.
An important document in this respect is the so-called Chronography of 354, basically the Roman version of Wikipedia, attributed to the scribe and calligrapher Filocalus. The year 354 is interesting, as it is about halfway between the recognition of Christianity as an official religion by the 313 Edict of Milan and the establishment of (orthodox) Christianity as the state religion of the Roman Empire in the 390s. The Chronography is a collection of both secular and religious information. Apart from the birthdays of the emperors and a list of the consuls we also find a calendar – the so-called Filocalian calendar – in which the eighth day before the kalendae of the month of January (i.e. 25 December) is mentioned as the birthday of the Invictus (N(ATALIS)·INVICTI).
It is interesting to compare this calendar, which is Part VI of the Chronography, to Part XII of the manuscript, which is about the Commemorations of the Martyrs. In this part, the entry for 25 December (or VIII kal. Ian.) is: NATVS CHRISTVS IN BETLEEM IVDEAE, or ‘Christ born in Bethlehem in Judea’. This is the oldest known reference to the birth of Christ on 25 December, and at the same time a strong indication that by the mid-fourth century this date was generally accepted by Christians as the date for Christmas. It is very tempting to see a connection between the birthday of Sol Invictus and Christmas, especially now that both events are mentioned in the same source for the same date. This is still no direct proof that the Christians copied the date of 25 December from the cult of the sun god, but we should note that in John 12:46, Christ claims that “I am come a light into the world, that whosoever believeth on me should not abide in darkness”. An association with the sun – and therefore the sun god – is therefore not improbable. I have previously written about a heavily damaged mosaic in the church of San Lorenzo Maggiore in Milan, which according to some historians depicts Christ-Sun in his chariot. A similar example can be found in the so-called Tomb of the Julii.
So how does Mithras fit into this story? The short answer is: he does not. The Mithraic cult was a mystery cult. Only initiates were granted admittance and these were exclusively male. The truth is that we know very little about the cult of Mithras. The ceremonies in the mithraea were held behind closed doors, the few written sources that we have were written by Christian opponents of the cult and the archaeological sources that we can study are reliefs and frescoes, which are not always easy to interpret. A lot of our ‘knowledge’ of Mithras relies on speculation. It is rather funny to note that, while some claim that Christianity enthusiastically copied from the cult of Mithras, it was the second century Christian apologist Justin Martyr who claimed the exact opposite: the wicked devils who worshipped Mithras had copied the celebration of the Eucharist from the Christians!
Franz Cumont (1868-1947), a Belgian archaeologist and historian, was a pioneer in the academic study of the cult of Mithras. Cumont assumed that Mithras had been born on 25 December, and so a connection between Mithras and Christmas was easily made. However, Cumont’s assumption was no more than that: an assumption. There is no evidence to back it up, not a single classical source mentions 25 December as Mithras’ birthday and Cumont’s theories have basically been abandoned since the 1970s, even by his initial followers. It seems much more plausible that participants in the Mithraic mysteries were themselves trying to link their cult to the official cult of Sol Invictus. The latter cult was a state cult, and as such generally accepted. The cult of Mithras, on the other hand, was a mystery cult, very popular with the military, and as such watched with suspicion by the authorities and at best tolerated. We know that Mithras is always mentioned as ‘sol invictus Mithras’ in ancient inscriptions, so there seems to be a clear link to the state cult of Sol Invictus. However, at the same time it is clear that Mithras is not the sun god himself. On reliefs, he is often depicted together with the sun god, with Sol riding in his four-horse chariot (see above) or having a banquet with Mithras, Luna (i.e. the Moon) and Mithras’ two attendants, Cautes and Cautopates.
So to sum up, the claim that 25 December derives from the cult of Mithras is not very convincing, to put it mildly. Likewise, many of the other stories about the influence of the Mithraic cult on Christianity are not very plausible either. I have read the claim that the word ‘mitre’ (μίτρα in Greek) derives from the word Mithras (Μίθρας). Anyone with basic knowledge of the Greek language and the Greek alphabet can see that this makes no sense from a linguistic point of view. And in any case, the word μίτρα is much, much older. It can already be found in the works of Homer and Herod. We can also find the claim that followers of Mithras had a sign of the cross on their foreheads. This is apparently based on a passage in Tertullianus’ work De Praescriptione Haereticorum. However, this church father never mentions a sign of the cross. The verb he used – signare – can mean any kind of mark. In the Palazzo Altemps in Rome, one can admire the so-called Grand Ludovisi sarcophagus. The figure of the deceased on this sarcophagus is marked with an X on his forehead. This has led some historians to conclude that the deceased must have been a follower of Mithras, although the evidence is quite thin.
The claim that Mithras, like Jesus, was born from a Virgin, is simply ludicrous. He was, in fact, born from a rock, a fact that is actually backed up by archaeological evidence. On the other hand, there is no evidence whatsoever that Mithras had twelve apostles, nor that he died on the cross. Finally, if you ever happen to read that there is a mithraeum beneath the Dutch-Reformed Church in Elst, the Netherlands, please know that you should not take the author seriously. I have no clue as regards the origins of this claim, but the truth is that the aforementioned church was built over the ruins of two Roman temples that were dedicated to Hercules Magusanus, the chief deity of the Batavi.
 Orthodox Christians celebrate Christmas on 25 December according to the Julian calendar, which corresponds to 7 January in the Gregorian calendar.
 Unless we accept some kind of duality, like the Holy Trinity in Christianity.