Leto

When Hera, the goddess of marriage and family, and the wife of Zeus, discovered that Leto was pregnant by Zeus, Hera banned Leto from giving birth on "terra firma", the mainland, any island at sea, or any place under the sun.

But Leto for her intrigue with Zeus was hunted by Hera over the whole earth, till she came to Delos and brought forth first Artemis, by the help of whose midwifery she afterwards gave birth to Apollo.

Leto found the barren floating island of Delos, still bearing its archaic name of Asterios, which was neither mainland nor a real island and gave birth there, promising the island wealth from the worshippers who would flock to the obscure birthplace of the splendid god who was to come. As a gesture of gratitude, Delos was secured with four pillars and later became sacred to Apollo. By contrast, according to the Homeric Hymn to Delian Apollo, Leto labored for nine nights and nine days for Apollo, in the presence of all the first among the deathless goddesses as witnesses: Dione, Rhea, Ichnaea, Themis and the sea-goddess Amphitrite. Only Hera kept apart, perhaps to kidnap Eileithyia, the goddess of childbirth, to prevent Leto from going into labor. Instead, Artemis, having been born first, assisted with the birth of Apollo. Another version, in the Homeric Hymn to Delian Apollo and in an Orphic hymn, states that Artemis was born before Apollo, on the island of Ortygia, and that she helped Leto cross the sea to Delos the next day to give birth to Apollo there.