SOL INVICTUS. Worship of the sun god, Sol, was known in republican Rome, but it was of minor importance. In imperial Rome, however, in the third century CE (the last century of pagan Rome), the cult of the sun god became a major and, at times, dominant force in Roman religion. The cult of the Syrian sun god from Emesa, installed at Rome under the emperor Elagabalus (218–222), was short-lived, but in 274 the emperor Aurelian began a vigorous campaign of propaganda celebrating the sun god as the exclusive protector of Rome's imperial might. Under the epithets oriens ("the rising one"), invictus ("the invincible one"), and comes Augusti ("comrade of Augustus"), Sol was hailed as "the rising sun who dispels the forces of evil," as "invincible conqueror of Rome's enemies," and as the "companion and guardian deity of the emperor."

Numismatic iconography, the primary source for this propaganda...