Halo (religious iconography)

A halo (from Greek ἅλως, halōs; also known as a nimbus, aureole, glory, or gloriole) is a ring of light that surrounds a person in art. They have been used in the iconography of many religions to indicate holy or sacred figures, and have at various periods also been used in images of rulers or heroes. In the sacred art of Ancient Greece, Ancient Rome, Hinduism, Buddhism, Islam and Christianity, among other religions, sacred persons may be depicted with a halo in the form of a circular glow, or flames in Asian art, around the head or around the whole body—this last one is often called a mandorla. Halos may be shown as almost any colour or combination of colours, but are most often depicted as golden, yellow or white when representing light or red when representing flames.

Homer describes a more-than-natural light around the heads of heroes in battle. Depictions of Perseus in the act of slaying Medusa, with lines radiating from his head, appear on a white-ground toiletry box in the Louvre and on a slightly later red-figured vase in the style of Polygnotos, ca. 450-30 BC, in the Metropolitan Museum of Art. On painted wares from south Italy radiant lines or simple haloes appear on a range of mythic figures: Lyssa, a personification of madness; a sphinx; a sea demon; and Thetis, the sea-nymph who was mother to Achilles. The Colossus of Rhodes was a statue of the sun-god Helios and had his usual radiate crown (copied for the Statue of Liberty). Hellenistic rulers are often shown wearing radiate crowns that seem clearly to imitate this effect.

...
Wikipedia