Sol Invictus
Sol Invictus was the official sun god of the later Roman Empire and a patron of soldiers. On 25 December AD 274, the Roman emperor Aurelian made it an official cult alongside the traditional Roman cults. Scholars disagree about whether the new deity was a refoundation of the ancient Latin cult of Sol, a revival of the cult of Elagabalus, or completely new. The god was favored by emperors after Aurelian and appeared on their coins until the last third-part of the reign of Constantine I. The last inscription referring to Sol Invictus dates to AD 387, and there were enough devotees in the fifth century that the Christian theologian Augustine found it necessary to preach against them.
''Invictus'' as epithet
Invictus was an epithet utilized for several Roman deities, including Jupiter, Mars, Hercules, Apollo, and Silvanus. It had been in use from the 3rd century BC. The Roman cult to Sol is continuous from the "earliest history" of the city until the institution of the Christian cult as the exclusive state religion. Scholars have sometimes regarded the traditional Sol and Sol Invictus as two separate deities, but the rejection of this view by S. E. Hijmans has found supporters.An inscription of AD 102 records a restoration of a portico of Sol in what is now the Trastevere area of Rome by a certain Gaius Iulius Anicetus. While he may perhaps have had in mind an allusion to his own cognomen, which is the Latinized form of the Greek equivalent of invictus, ἀνίκητος, the earliest extant dated inscription that uses invictus as an epithet of Sol is from AD 158. Another, stylistically dated to the 2nd century, is inscribed on a Roman phalera : inventori lucis soli invicto augusto Augustus is a regular epithet linking deities to the Imperial cult.
Sol Invictus played a prominent role in the Mithraic mysteries, and was equated with Mithras. The relation of the Mithraic Sol Invictus to the public cult of the deity with the same name is unclear and perhaps non-existent.
Elagabalus
According to the Historia Augusta, Elagabalus, the teenaged Severan heir, adopted the name of his deity and brought his cult image from Emesa to Rome. Once installed as emperor, he neglected Rome's traditional State deities and promoted his own as Rome's most powerful deity. This ended with his murder in 222. The Historia Augusta refers to the deity Elagabalus as "also called Jupiter and Sol". While this has been seen as an attempt to import the Syrian sun god to Rome, the Roman cult of Sol had existed in Rome since the early Republic.Aurelian
The Roman gens Aurelia was associated with the cult of Sol. After his victories in the East, the Emperor Aurelian thoroughly reformed the Roman cult of Sol, elevating the sun-god to one of the premier divinities of the Empire. Where previously priests of Sol had been simply sacerdotes and tended to belong to lower ranks of Roman society, they were now pontifices and members of the new college of pontifices instituted by Aurelian. Every pontifex of Sol was a member of the senatorial elite, indicating that the priesthood of Sol was now highly prestigious. Almost all these senators held other priesthoods as well, however, and some of these other priesthoods take precedence in the inscriptions in which they are listed, suggesting that they were considered more prestigious than the priesthood of Sol. Aurelian also built a new temple for Sol, which was dedicated on December 25, 274, and brought the total number of temples for the god in Rome to four. He also instituted games in honor of the sun god, held every four years from 274 onwards.The identity of Aurelian's Sol Invictus has long been a subject of scholarly debate. Based on the Augustan History, some scholars have argued that it was based on Sol Elagablus of Emesa. Others, basing their argument on Zosimus, suggest that it was based on the Šams, the solar god of Palmyra on the grounds that Aurelian placed and consecrated a cult statue of the sun god looted from Palmyra in the temple of Sol Invictus. Professor Gary Forsythe discusses these arguments and adds a third more recent one based on the work of Steven Hijmans. Hijmans argues that Aurelian's solar deity was simply the traditional Greco-Roman Sol Invictus.
Constantine
Emperors portrayed Sol Invictus on their official coinage, with a wide range of legends, only a few of which incorporated the epithet invictus, such as the legend SOLI INVICTO COMITI, claiming the Unconquered Sun as a companion to the Emperor, used with particular frequency by Constantine. Statuettes of Sol Invictus, carried by the standard-bearers, appear in three places in reliefs on the Arch of Constantine. Constantine's official coinage continues to bear images of Sol until 325/6. A solidus of Constantine as well as a gold medallion from his reign depict the Emperor's bust in profile twinned with Sol Invictus, with the legend INVICTUS CONSTANTINUSConstantine decreed dies Solis—day of the Sun, "Sunday"—as the Roman day of rest
Constantine's triumphal arch was carefully positioned to align with the colossal statue of Sol by the Colosseum, so that Sol formed the dominant backdrop when seen from the direction of the main approach towards the arch.
Sol and the other Roman Emperors
Berrens deals with coin-evidence of Imperial connection to the Solar cult. Sol is depicted sporadically on imperial coins in the 1st and 2nd centuries AD, then more frequently from Septimius Severus onwards until AD 325/6. Sol invictus appears on coin legends from AD 261, well before the reign of Aurelian.Connections between the imperial radiate crown and the cult of Sol are postulated. Augustus was posthumously depicted with radiate crown, as were living emperors from Nero to Constantine. Some modern scholarship interprets the imperial radiate crown as a divine, solar association rather than an overt symbol of Sol; Bergmann calls it a pseudo-object designed to disguise the divine and solar connotations that would otherwise be politically controversial but there is broad agreement that coin-images showing the imperial radiate crown are stylistically distinct from those of the solar crown of rays; the imperial radiate crown is depicted as a real object rather than as symbolic light. Hijmans argues that the Imperial radiate crown represents the honorary wreath awarded to Augustus, perhaps posthumously, to commemorate his victory at the Battle of Actium; he points out that henceforth, living emperors were depicted with radiate crowns, but state divi were not. To Hijmans this implies the radiate crown of living emperors as a link to Augustus. His successors automatically inherited the same offices and honours due to Octavian as "saviour of the Republic" through his victory at Actium, piously attributed to Apollo-Helios. Wreaths awarded to victors at the Actian Games were radiate.
Festival of Dies Natalis Solis Invicti
The Philocalian calendar of AD 354 gives a festival of "Natalis Invicti" on 25 December. There is limited evidence that this festival was celebrated before the mid-4th century. Whether this date was intended to celebrate solstice is doubtful; one scholar writes that "the cult of the Sun in pagan Rome ironically did not celebrate the winter solstice nor any of the other quarter-tense days, as one might expect".Since the 12th century, there have been speculations that the near-solstice date of 25 December for Christmas was selected because it was the date of the festival of Dies Natalis Solis Invicti.
Legacy
Christianity
According to many historians, Christmas was set to December 25th because it was the date of the festival of Sol Invictus. This idea became popular especially in the 18th and 19th centuries.The charioteer in the mosaic of Mausoleum M has been interpreted by some as Christ. Clement of Alexandria had spoken of Christ driving his chariot across the sky. This interpretation is doubted by others: "Only the cross-shaped nimbus makes the Christian significance apparent", and the figure is seen by some simply as a representation of the Sun with no explicit religious reference whatever, pagan or Christian.