Caelus

Mithraic altar (3rd-century AD) showing Caelus flanked by allegories of the Seasons (Museum Carnuntinum, Lower Austria)

Caelus or Coelus (/ˈsləs/; SEE-ləs) was a primordial god of the sky in Roman mythology and theology, iconography, and literature (compare caelum, the Latin word for "sky" or "heaven", hence English "celestial"). The deity's name usually appears in masculine grammatical form when he is conceived of as a male generative force.