Melian was a Maia of the people of Vana and Este, who in the deeps of time dwelt in the gardens of Lorien in Valinor, where her voice and the song of her nightingales were renowned even among the Valar. Coming into Middle-earth in the Elder Days, she met the Elf-lord Elwe in the starlit woods of Nan Elmoth, and such was the enchantment of their meeting that they stood together in love and silence while long years passed and the Great Journey of his people went on without him. So Elwe -- Thingol -- remained in Beleriand, and Melian became his queen.
Together they raised the hidden kingdom of Doriath, and about its borders Melian wove a fence of shadow and bewilderment, the Girdle of Melian, which none could pass against her will; thus Doriath stood unconquered while realms greater in arms fell to Morgoth. She was the mother of Luthien Tinuviel, fairest of all the Children of Iluvatar, and through Luthien her divine blood passed into the line of Elrond and Elros, and so to Arwen and Aragorn and the kings that came after. When Thingol was slain over the Nauglamir, Melian's grief unbound her power; the Girdle failed, Doriath lay open to its foes, and she forsook Middle-earth and returned to the gardens of Lorien, and came never back.