Sol Invictus

The Saturnalia was perhaps the most popular of Roman holidays. Catullus wrote to his friend Calvus circa 57-54 BCE that is was "optimus dierum", the first of festivals. His note was in response to a Saturnalia gift that turned out the be a bit of a practical joke - Catullus was expecting quality poetry from his friend Calvus but was disappointed to find the book filled with the poor work of poetasters, meaning mediocre or untalented poets. (See: Commentary on Catullus)

"Great Gods! What horrid booklet damnable
Unto thine own Catullus thou (perdie!)
Did send, that ever day by day die he
In Saturnalia, first of festivals.
No! No! thus shall't not pass wi' thee, sweet wag,
For I at dawning day will scour the booths
Of bibliopoles, Aquinii, Caesii and
Suffenus, gather all their poison-trash
And with such torments pay thee for thy pains.
Now for the present hence, adieu! begone"
-Catullus, Letter to Calvus

H. H. Scullard's 1981 book on "Festivals and Ceremonies of the Roman Republic" describes the timing of Saturnalia:

"The festival was held around the time of the winter solstice, a season when mankind in many places and at many periods has felt the need for rest and merry-making, not least at our own time of Christmas."
-Scullard, p.205

And goes on to mention:

"The celebration of the Nativity of Christ on 25 December, just after the Saturnalia, is first attested in teh CAlendar of Philocalus in AD 336, and the day may have been chosen tin opposition to the festival held that day in honor of Sol Invictus, wholse temple was dedicated in AD 274 by Aurelian.  However that may be, the Christians celebrated a period of goodwill when families and friends dfeasted together , exchanged presents, and ever some times wore paper hats (pilei?)"
-Scullard, p.205

The sheer numbers of coins with Aurelian and Sol make this coin a first thought for a Roman coin depicting Sol (https://ric.mom.fr/en/coin/2637)

Aurelianus, Rome, CE 274, AR Antoninianus

Obv: IMP AVRELIANVS AVG, Bust right, radiate, cuirassed (B01)

Rev: ORIENS AVG, Sol stg. facing, head left, with right hand raised and holding globe in left hand; at feet to left, a bound and seated captive in Asian dress. ( –|-//S)

Ref: RIC temp #2637

However, Sol was not a new god to Rome in the time of Aurelian. Elagabalus introduced and Emesan sun-god to Rome and on this coin declares himself the SACERD DEI SOLIS or priest of the Sun God Elagabalus.

Elagabalus, AD 218-222. AR, Denarius (2.62g, 20mm), Rome, 218-222.

Obv: IMP ANTONINVS PIVS AVG, laureate, horned and draped bust right

Rev: SACERD DEI SOLIS ELAGAB, Elagabalus standing right, sacrificing over lighted altar, holding patera and club; star in right fields.

On this provincial coin from Cilicia from the reign of Domitian, the sun god is made to look like Domitian with Luna/Selene the Moon god on the reverse.

Roman Provincial, Domitian Æ (6.65g, 23mm, 12h) of Aegeae, Cilicia. Dated CY 135 = 88/9. Herakleon, magistrate.

Obv: Radiate head of Apollo-Phoibos (phoibos meaning shining or bright) with features of Domitian to right; laurel branch in right field

Rev: Draped bust of Artemis-Selene to left, crescent set on forehead, quiver over shoulder; ΑΙΓΕΑΙΩΝ behind, ΗΡΑΚΛΕΩΝΟϹ below, ЄΛΡ (date) in left field

Ref: RPC II 1776A (this coin specimen 3 of 3, additional coin-type added post publication); Haymann 24b. This coin is very rare.

There is a debate about Sol: whether or not Sol Indigetes is a different Sol from the one that became popular in the 3rd Century, Heliogabalus or Sol Invictus under the influence of Syria.

Recently S.E. Hijmans provided a lengthy argument against Sol Invictus (of Syrian origin) being a different god from Sol Indigetes. He argues that Sol Indiges and Sol Invictus are the same god, primarily rejecting the widely held view that they were separate due to Sol Invictus being considered an "oriental" import.

• Sol was a longstanding part of Roman religious life, with roots in the Republic and earlier. Sol Indiges, a traditional Roman god, was worshiped alongside Luna and had a place in the early Roman pantheon.

• The term "Invictus" does not mark Sol as a distinct deity but is rather a general epithet used for several Roman gods, including Jupiter and Mars.

• There is little or no evidence of Sol Invictus as a Syrian import. The iconography of Sol, even in the time of Aurelian, remains distinctly Roman, not reflecting any clear oriental elements. This suggests that Aurelian's promotion of Sol Invictus was a continuation and elevation of the existing Roman solar deity, not the introduction of a new, foreign god.

• Sol's image remained stable on coins for centuries, with no evidence suggesting a fundamental transformation in the god's nature or cult.

See: Hijmans, S. E. Sol: The Sun in the Art and Religions of Rome. PhD thesis, University of Groningen, 3 Sept. 2009, [s.n.].

Sol was an ancient Roman god. King Tatius, the Sabine King who ruled with Romulus, dedicated altars in Rome to the Sun and Moon.

Here are two coins from Antony that show Sol on the reverse. Mark Antony minted coins with the head of Sol, he and Octavian were heading from Rome to Macedonia in pursuit of the murderers of Julius Caesar or Liberators of the Roman people, Brutus and Cassius. They would defeat them in two battles in October AD 42 at Philippi with Cassius committing suicide in the first battle and Brutus in the second that ended October 23rd. Sol in the context of this coin was anticipating and/or celebrating victory over the assassins of Julius Caesar at Phillippi.

and an even earlier depiction of Sol on this denarius from the Roman Republic:

Man. Aquillius. 109-108 BC. AR Denarius. Rome mint.

Obv: Radiate head of Sol right; X (mark of value) below chin

Rev: Luna driving galloping biga right; crescent moon and three stars above, one star below.

Note a similar looking Sol from Cilicia from the 1st century BC

Cilicia, Soloi, AE, circa 100-30 BC

Obv: Radiate head (of Helios?) right; monogram to left.

Rev: ΣOΛEΩN, Athena seated left on throne, resting arm upon round shield and holding Nike

Syncretism and Panentheism

It seems to me quite likely that the Roman Sol and other sun gods (and even the cult of the emperor) blended ambiguously over time. Such syncretism was not uncommon across the Roman Empire as cultures and religions intermingled.

Marcus Aurelius, 2nd century Roman emperor, expresses a philosophy which sounds panentheistic - a belief that the divine permeates everything and is greater than any single god or the sum of all gods. Individual deities are viewed as different expressions or aspects of one ultimate, transcendent reality.

"Everything harmonizes with me, which is harmonious to thee, O Universe. Nothing for me is too early nor too late, which is in due time for thee. Everything is fruit to me which thy seasons bring, O Nature: from thee are all things, in thee are all things, to thee all things return. The poet says, Dear city of Cecrops; and wilt not thou say, Dear city of Zeus?"
- Meditations, 4.23