Sol Invictus

• 1. Introduction

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  Sol Invictus, the Unconquered Sun, burned at the center of Roman religious life for over a century. On the 25th of December 274 AD, the emperor Aurelian dedicated a brand-new temple to the sun god in Rome, a building that brought the total count of Sol's temples in the city to at least four. That same year, Aurelian declared Sol Invictus the chief deity of the entire Roman Empire. It was an act of religious transformation so sweeping that coins depicting the sun god would circulate in Roman hands for decades to come.

  Who was this god, exactly? That question has never been settled. Was Sol Invictus a Syrian import, a foreign deity carried to Rome on the ambitions of a teenage emperor? Or was he the same sun god Romans had always worshipped, simply raised to a new level of official prestige? Scholars have been arguing about this for generations, and the debate is far from over.

  Then there is the question of December 25. Long before Christmas, the Romans may have celebrated the birthday of the Invincible Sun on that date. The connection between Sol Invictus and the birth of Jesus Christ is one of the most contested claims in the history of religion. The last known inscription referring to Sol Invictus dates to 387 AD, but the arguments he left behind have never quite faded.

• 2. One God or Two

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  S. E. Hijmans, whose revisionist scholarship has reshaped the field, argues that there was only ever one cult of Sol in Rome, running without interruption from the monarchy all the way to the end of antiquity. At least three temples of Sol stood in Rome during the Empire, and all three dated from the earlier Republic. This continuous presence is the foundation of the revisionist case.

  The traditional view tells a different story. In that reading, there were two distinct sun gods separated by centuries. The first, Sol Indiges, was an early Roman deity of minor importance whose cult had largely faded by the first century AD. The second, Sol Invictus, was believed to be a Syrian sun god whose cult was first introduced in Rome under the emperor Elagabalus. Elagabalus brought the cult image of his deity from the Syrian city of Emesa and, once emperor, sidelined Rome's traditional gods in favor of this new one. His murder in 222 AD ended that experiment abruptly.

  The epithet "Invictus" itself does not belong exclusively to Sol. It was applied to Jupiter, Mars, Hercules, Apollo, and Silvanus, and had been in use since the third century BC. The earliest dated inscription applying "Invictus" specifically to Sol comes from 158 AD. An inscribed ornamental disk, stylistically dated to the second century, carries the phrase meaning "I glorify the unconquerable sun, the creator of light".

• 3. Aurelian's Reform

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  Aurelian's own family name carried solar associations. The Roman clan, or gens, Aurelia had long been linked to the cult of Sol, which makes his later actions feel almost dynastic. After a string of military victories in the East, he overhauled the entire structure of Sol's priesthood from the ground up.

  Before Aurelian, priests of Sol held the rank of sacerdotes and typically came from the lower ranks of Roman society. Aurelian abolished that arrangement. He created a new college of pontifices, and every priest of Sol in this new order was a member of the senatorial elite. The change in social standing was dramatic. Almost all of these senators also held other priesthoods, and those other roles sometimes took precedence in official inscriptions, suggesting that even in this elevated form, Sol's priesthood was not always the most prestigious rank a senator held.

  Aurelian also established athletic and competitive games in honor of Sol, held on a four-year cycle starting from 274 AD. The question of whether these reforms drew on the Syrian solar cult of Emesa, the solar deity Malakbel of Palmyra, or simply the traditional Greco-Roman sun god remains unresolved. The scholar Forsythe, writing in 2012, examined all three positions without reaching a definitive answer.

• 4. Constantine and the Sun

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  Constantine I used the legend claiming the "Unconquered Sun" as a companion to the emperor with particular frequency on his official coinage. Statuettes of Sol Invictus, carried by standard-bearers, appear in three separate places in the relief carvings on the Arch of Constantine. The arch itself was deliberately positioned to align with the colossal statue of Sol that stood near the Colosseum, so that anyone approaching the arch from the main direction would see Sol as the dominant backdrop behind it.

  A gold solidus and a gold medallion from Constantine's reign both show the emperor's profile side by side, or jugate, with the image of Sol Invictus. His official coinage continued bearing images of Sol until 325-326 AD. Then, on the 7th of March 321, Constantine issued a decree designating the day of the Sun as the Roman day of rest. The text of the decree required magistrates and city dwellers to rest and close their workshops, while allowing agricultural workers to continue planting and harvesting when conditions made delay costly.

  Hijmans has proposed that the imperial radiate crown, worn by emperors from Nero onward after 65 AD, represents not a solar symbol but the honorary wreath awarded to Augustus after his victory at the Battle of Actium. In Hijmans's reading, the radiate crown was a symbol of the Augustan legacy, which each emperor inherited. The wreaths awarded to victors at the Actian Games were also radiate, and state divi, unlike living emperors, were not depicted with them.

• 5. December 25 and the Debate

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  The festival known as Dies Natalis Solis Invicti, or "birthday of the Invincible Sun," is associated by many scholars with the 25th of December, which fell on the date of the winter solstice in the Roman calendar. In Rome, the yearly celebration reportedly involved thirty chariot races. Gary Forsythe, Professor of Ancient History, has noted that this date placed the festival within easy reach of the Saturnalia, Rome's most celebrated holiday season, which ran from December 17-23 and was marked by parties, banquets, and the exchange of gifts.

  Before Aurelian, around 238 AD, the writer Censorinus had referred to the winter solstice as the "birth of the Sun" in his work De Die Natali. The Calendar of Antiochus of Athens, from roughly the second century AD, had marked December 25 as the "birthday of the Sun" without mentioning any religious festival being held on that day.

  The Chronograph of 354, also called the Calendar of Filocalus, marks the Natalis Invicti on December 25. Historians generally date the relevant portion of that text to 336 AD, written in Rome. Hijmans disputes whether this entry refers to Sol Invictus at all, pointing out that the festival name omits "Sol" and that the number of chariot races assigned to it is not a multiple of twelve, unlike other confirmed feasts of Sol. Wallraff, writing in 2001, concluded that evidence for the festival before the mid-fourth century is limited.

  The emperor Julian addressed the Agon Solis, a sacred contest for Sol instituted by Aurelian on a four-year cycle, in his Hymn to King Helios written in 362 AD. Julian placed it in late December, between the end of the Saturnalia and the New Year, and described it as dedicated to Helios and the "Invincible Sun." Hijmans reads this differently, arguing that Julian never explicitly said the Agon Solis fell on December 25 and may have been describing a separate winter solstice festival of Sol.

• 6. Sol and Christianity

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  The Calendar of Filocalus from around 336 AD is the earliest record that places both the Natalis Invicti and the birthday of Christ on December 25. The widely held hypothesis is that the early Church chose that date for Christmas to absorb the solar festival. Hijmans has inverted this argument, suggesting that the pagan feast on December 25 might have developed as a reaction to the Christian one rather than the other way around.

  An alternative calculation for the date of Christmas runs through the Annunciation. The French priest and historian Louis Duchesne proposed in 1889 that Christmas was calculated as nine months after March 25, which the Romans treated as the date of the spring equinox and which the Church observed as the date of Christ's conception.

  The early Church applied solar language directly to Christ. He was called Sol verus, the true Sun, and Sol Justitiae, the Sun of Righteousness, a title drawn from the prophet Malachi. The late-fourth-century Christian treatise De solstitiis et aequinoctiis makes the identification explicit, describing Christ's birth as coinciding with the "birthday of the sun" and directly addressing the pagan term "Invictus."

  Augustine of Hippo preached on the same tension in a Christmas sermon, urging his congregation to honor the day not because of the sun but because of the one who made the sun. That Augustine felt obliged to address solar devotion at all reflects the persistence of the cult. His sermons against Sol's worshippers were still necessary in the fifth century, decades after the last known dated inscription for Sol Invictus, which was carved in 387 AD.

  A mosaic dated to around 300 AD in the Tomb of the Julii, a tomb found in the Vatican Necropolis and considered Christian, is generally read as depicting Christ in the guise of Sol, Helios, or Apollo. Hijmans has cautioned that the figure may simply represent Sol himself. In the synagogues of late antiquity, Sol Invictus appeared as well: floor mosaics at Hamat Tiberias, Beth Alpha, Husefa, and Naaran in the West Bank show him in the central roundel of zodiac compositions, sometimes in a four-horse chariot, rendered with the familiar radiate halo.