Caelus (also Coelus) is the Roman personification of the sky, the counterpart of the Greek Uranus, whose name is the root of the word celestial. Unlike Jupiter, the active sky-god of storm and state, Caelus is a theological and poetic figure with little independent cult, more a way of speaking about the vault of heaven than the recipient of festivals. He appears chiefly in cosmological and philosophical contexts and in imperial art, where the emperor is sometimes shown raised up beneath a canopy held by a figure of Caelus, marking the heavens as the frame of Roman power. In the mystery cult of Mithras a figure identified with Caelus appears among the cosmic imagery, and antiquarian writers used him to render the Greek Ouranos in genealogies of the gods. His name is set in this atlas as the mythic face of the planet Uranus.
The Latin poet Ennius, in his translation of the Greek writer Euhemerus's Sacred History in the early second century BCE, popularised at Rome a rationalising reading of divine genealogy in which Caelus, Saturn and Jupiter were understood not as literal gods but as a line of ancient kings later deified by grateful or awestruck subjects, with Caelus cast as the first great ruler of a primitive age whose son Saturn in turn fathered Jupiter. This euhemerist interpretation, treating myth as garbled history rather than literal theology, remained influential among Roman intellectuals and, through early Christian writers who found it a useful weapon against pagan belief, helped shape later Western habits of reading ancient mythology as a distorted memory of real events.