Sol Invictus or the unconquered sun was an image which became adopted by some early roman emperors (who wouldn’t want to be best buddies with something invincible?) Invictus was originally used to describe various deities in their war aspects, such as Jupiter invictus, or Mars invictus. It was well established in this use, when applied to Mithras by roman devotees from the 2nd century onwards. The earliest description of sol as invictus comes from Rome in 158AD:
Corpus Inscriptionum Latinarum VI, 715: Soli Invicto deo / ex voto suscepto / accepta missione / honesta ex nume/ro eq(uitum) sing(ularium) Aug(usti) P(ublius) / Aelius Amandus / d(e)d(icavit) Tertullo et / Sacerdoti co(n)s(ulibus)
(Publius Aelius Amandus dedicated this to the god Sol Invictus in accordance with the vow he had made, upon his honorable discharge from the equestrian guard of the emperor, during the consulship of Tertullus and Sacerdos);
from J. Campbell, The Roman army, 31 BC-AD 337: a sourcebook (1994), p. 43
Here he is, on the Pessinus silver disk which dates to the third century:
A priest called Chresimus dedicates a slab to Sol Invictus: Soli Invicto / pro salute Imp(eratorum) / et Genio n(umeri) eq(uitum) sing(ularium) / eorum M(arcus) Ulpius / Chresimus sace[r(dos)] / Iovis Doliche[ni] / v(otum) s(olvit) l(ibens) l(aetus) [m(erito)]
With roman inscriptions you often find that they shorten words down to one or two letters It works a bit like our ASAP, a shortened form of As Soon As Possible. In the above the letters within curved brackets are those letters which are understood to be missing through this. You will also see some letters, or words within square brackets, these are the letters which are missing through the inscription being damaged. They know what these are because romans have a nice set of standard formulas when writing out inscriptions. The important bits ( for us, in this case) are the words CHRESIMUS SACER(DOS) – which is a priest named Chresimus (three lines from the bottom), and the two words that the inscription starts with: SOLI INVICTO
He also appears on mosaics, as this 3rd C. one from Switzerland:
Probus (276-282AD) also wanted to associate himself with the unconquered sun in the minds of the romans; just in case the you missed the distinct spikey crown imagery, the emperor made sure by writing SOLI INVICTO on the reverse. Again, Sol is doing some righteous trampling, in a four horse chariot this time, just in case the spikey crown and words are not enough…
Two emperors was not enough, the big one, linking his image with that of Unconquered Sun was a chap called Constantine (Emperor 306-337 AD):
Again with the radiated solar crown imagery, just on Sol, as the emperor prefers to go with the traditional classic laurel wreath to denote victory and success…. The legend on the reverse reads SOLI INVICTO COMITI – in short, claiming the Unconquered Sun as companion to the Emperor. The second coin shown below is something a bit different: a double face coin, with the face of Sol (complete with solar crown) behind the face of Constantine. Just in case you don’t get it, the inscription begins INVICTUS CONSTANTINIUS. With Constantine things changed a tad. The statuettes of Sol Invictus carried by standard bearers appear in three places on the Arch of Constantine. Constantine’s official coinage bears legends relating to Sol Invictus until 323AD. He also decreed ‘dies Solis’ – The Day of the Sun, or Sunday – would be a day of rest. With a little help from his mother Helena, the Unconquered Sun began blurring with the Everlasting Son (of God)
From the fourth century there is an increasing assimilation of Christ to the Sun-god (as Sun of Righteousness), the Christos Helios (cf. Eusebius Life of Constantine 1.4.18). It didn’t start there, but had been merging for many years before: the theme of “Christ-the-True- Sun” had already been diffusely proclaimed by Clement of Alexandria (ca. 150-215AD) in many of his writings.
The assimilation of Helios-Sol-Christ, is shown best in this mosaic from the ceiling of the Mausoleum of the Julii, which is under St Peters Basilica in the Vatican. It dates to late 3rd- early 4th century. The lower vault walls contained images of Jonah, fishermen, and Good Shepherd, confirming the Christian nature of the mausoleum, and the syncretic nature of the Sol Invictus image:
Sol Invictus still existed separately from other deities, even at this late stage. The last inscription referring to Sol Invictus dates to 387 AD, and there were still enough devotees in the 5th century that Augustine found it necessary to preach against them.
So, from his earliest appearances as a deity of the sun, to god in his own right, to being associated with Roman Emperors and finally merged with Helios-Christ in imagery which would have been familiar to most, Sol Invictus has risen this morning in a blazing chariot to fill our world with light and remind us that he is still as relevant now as ever.
You have returned O Sun, as I knew you would
for this is your part in the way of things
you have your role, and you play it well
I ask that you inspire me to do the same:
to know the right thing to do
and to do it with passion and joy and honour
This mosaic is part of a series representing days of the week: the one above is Sunday (which I’ll talk more about later)
But where does he come from, this Unconquered Sun-God? For that we’ll have to leave the romans for a while and come back to them later. As with a lot of early deities, Sol Invictus is a bit tricky to isolate from other deities: originally his name was simply a title attributed to other deities, such as Mithras, Elagabalus and Sol. He also performed similar roles to Helios, Apollo and local sun deities, which would have been known to the romans. Unlike the earlier, agrarian cult of Sol Indiges (the native sun or the invoked sun – the etymology and meaning of the word indiges is disputed), the title Deus Sol Invictus was formed by analogy with the imperial titulature pius felix invictus (dutiful, fortunate, unconquered).
Now back to the romans, who really cornered the market: the Roman Emperor Elagabalus (218-222, possibly the most amusing emperor since Caligua – wedding of a goddess to a rock anyone?) introduced a festival for the sun in the middle of winter. The use of the title Sol Invictus allowed several solar deities to be worshipped collectively, including Elagabalus, a Syrian sun god (after whom he got his nickname, also the patron of Aurelian) and Mithras. Note the crown covered in spikes, or rays, known as a ‘radiated solar crown’ in the illustrations above as it appears here as well: Emperor Aurelian (270-275AD) made coins linking himself with images of Sol, this one was minted 274-275AD (so right at the end of his reign): note the radiated solar crown as distinct imagery in both the face and reverse sides:
A face of the emperor looks right on the front of the coin, and a figure of Sol is on the reverse. Here the image of Sol is that of laying the unconquered smackdown on some poor unfortunate. Aurelian’s deliberate propaganda through coinage is saying “Aurelian is unconquered like Sol”. Aurelian introduced solar pantheism, which was consequently absorbed by the pantheon of existing roman deities.
After his victories in the East, the emperor Aurelian introduced an official cult of Sol Invictus, making the sun-god the premier divinity of the empire, and wearing his radiated crown himself. Hijmans (Hijmans, Steven E (2009) (Thesis/dissertation), Sol : the sun in the art and religions of Rome, ISBN 9036739314) lists the known festivals of Sol as August 8 and/or 9, August 28, and December 11. There are no sources that indicate on which day Aurelian inaugurated his temple and held the first games for Sol, but we do know that these games were held every four years from 274 onwards. This means that they were presumably held in 354, a year for which perchance a Roman calendar, the Chronography of 354 (or calendar of Filocalus), has survived. This calendar lists a festival for Sol and Luna on August 28, Ludi Solis (games for Sol) for October 19–22, and a Natalis Invicti (birthday of the invincible one) on December 25. While it is widely assumed that the invictus of December 25 is Sol, the calendar does not state this explicitly. The only explicit reference to a celebration of Sol in late December is made by Julian the Apostate in his hymn to King Helios written immediately afterwards in early CE 363. Julian explicitly differentiates between the one-day, annual celebration of late December 362 and the multi-day quadrennial games of Sol which, of course, had also been held in 362, but clearly at a different time. Taken together, the evidence of the Calendar of Filocalus and Julian’s hymn to Helios clearly shows, according to Hijmans and others, that the ludi of October 19–22 were the Solar Games instituted by Aurelian. They presumably coincided with the dedication of his new temple for Sol. The cult of Sol Invictus became the leading official sun cult of the fourth century. In the legions, where a policy of individual religious freedom is attested by personal inscriptions, on shrines and through votive offerings in every part of the Empire, outside the camps themselves, the only Eastern cult that was officially tolerated, probably from Aurelian’s reign, and certainly under Constantine, was that of Sol Invictus.
Aurelian is not the only emperor to associated himself with Sol Invictus through his coinage: