One of Zeus' many lovers was the goddess Leto. When Leto was pregnant with his twin children, Apollo and Artemis, Hera, as you would expect, was madly jealous. She compelled all the lands of the earth to refuse to allow Leto a place where she could give birth. Finally, Leto found refuge on the floating island of Delos which was not attached in any way to the earth, and this was where she gave birth to her twins.
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