IRIS was the goddess of the rainbow, the messenger of the Olympian gods. She was often represented as the handmaiden and personal messenger of Hera. Iris was a goddess of sea and sky--her father Thaumas "the wondrous" was a marine-god, and her mother Elektra "the amber" a cloud-nymph.
For the coastal-dwelling Greeks, the rainbow's arc was most often seen spanning the distance beteween cloud and sea, and so the goddess was believed to replenish the rain-clouds with water from the sea.
Iris had no distinctive mythology of her own. In myth she appears only as an errand-running messenger and was usually described as a virgin goddess. Her name contains a double meaning, being connected both with iris, "the rainbow," and eiris, "messenger."