When the Titaness Leto became pregnant with Zeus's children, the jealous goddess Hera forbade any land on earth to give her shelter to give birth. Leto wandered in agony until she found Delos, a barren, floating island that was not attached to the ocean floor, and thus exempt from Hera's curse. There, grasping a palm tree, Leto gave birth first to Artemis, goddess of the hunt, who then immediately helped her mother deliver Apollo, god of light and music.
In gratitude, the island was anchored securely to the seabed by four pillars, becoming one of the most sacred sanctuaries in the Greek world.