The term intaglio refers to a small image that has been engraved into a gemstone and usually set in a piece of jewellery, most commonly a ring. Such artistic form has its origin in Sumer in the 4th millennium BC, with the appearance of cylinder and stamp seals, whereby decorations and patterns were engraved into soft stones. During the Hellenistic period and the early Roman Empire, the art of intaglio reached its apogee, with there being a steady decline in craftsmanship in the late Imperial Rome, until a revival of interest with the Byzantine and during the Renaissance.
The subject used for intaglios are diverse, with depictions of deities being a favourite theme. Apollo, who was known to the Romans as Phoebus, was one of the most important deities in the Graeco-Roman canon. He was the god of oracles, healing, the sun, and poetry among other attributes. His multivalent nature, importance, and prevalence in mythology means that he was a popular deity both for worship and for artistic interpretation. He was the son of Zeus and Leto, and was a twin with Aretmis (goddess of the hunt). He had key sanctuaries at Delos and Rhodes – with Rhodes being famous for one of the seven wonders of the ancient world.