Helios was especially worshipped in Rhodes, where from at least the early 5th century BCE he was regarded as the chief god, to whom the island belonged. His worship spread as he became increasingly identified with other deities, often under Eastern influence. From the 5th century BCE, Apollo, originally a deity of radiant purity, was more and more interpreted as a sun god. Under the Roman Empire the sun itself came to be worshipped as the Unconquered Sun.Helios (also Helius) was the god of the Sun in Greek mythology.