Aredhel, daughter of Fingolfin, dwelt with her brother Turgon in the hidden city of Gondolin, and quickly, she became wearied by her lack of freedom there. Reluctantly, Turgon granted her leave to visit their brother Fingon, although bad tidings were portended to him. Aredhel, though, had different plans, and instructed her escort that they would instead seek the sons of Fëanor, with whom she’d been friends in Valinor. They were not permitted admittance into Doriath—being not of Finarfin’s house—but passed between the northern border of Doriath and the treacherous Ered Gorgoroth, where the group became lost in shadows, and Aredhel was separated from her escort. They searched without finding her and were nearly killed; fearing that she was dead or captured, they returned to Gondolin with the bad news.
Aredhel, though, upon being separated from her companions, rode on alone, until she came to Himlad, the land of Celegorm and Curufin. The brothers were not at home, but the people of Celegorm welcomed her, and she remained, wandering freely about their lands. Eventually, she wandered too far and into the forest of Nan Elmoth, where the enchantment of Melian still lay and the trees grew so tall and thick that the sun could not penetrate the canopy. There, Eöl—called Dark Elf—dwelt, preferring the twilight and night to the light of day. Eöl had befriended the Dwarves, and they learned much of each other. Often, he stayed with them in their kingdoms, and he had devised a metal from the skills that he learned called galvorn: dark and impenetrable but supple.
When Eöl saw Aredhel wandering in his forest, he desired her, and set such enchantments about her that she could not find her way out but was drawn ever-nearer to his home. When she arrived, he welcomed her, and he took her to wife, though she was not wholly unwilling and was happy for a time with Eöl. The couple had a son called Maeglin—“sharp glance”—who resembled in appearance the Noldor but in thought and mind was like his father. He spoke little but was very powerful when he did, and with his father, he went to the Dwarves and learned much from them, especially of delving ore from the mountains.
Despite this, he had a deep love for his mother and for his mother’s people, and he loved to hear tales of their deeds and especially of Turgon, who had no heir. Maeglin desired to seek others of the Noldor and was direly forbidden by his father, and the trust and friendship between them was broken. When Eöl was off to a midsummer feast with the Dwarves, Maeglin persuaded his mother to return to Gondolin. To the servants of Eöl, Aredhel told them that they sought the sons of Fëanor.
When Eöl returned, he pursued his wife and son and was taken by the people of Curufin. Curufin was angry that Eöl had taken Aredhel to wife and advised him to return to Nan Elmoth and said that Eöl's wife and child loved him no more. Eöl, though, was wrathful and knew then that his family was riding to Gondolin—not the sons of Fëanor—and pursued them, spotting them just as they arrived at the gates.
Aredhel and Maeglin were joyfully welcomed to the city, and Turgon was pleased with Maeglin and offered him the highest honors of his realm. Maeglin took Turgon as his lord and king and marveled at Gondolin—but most of all at the King’s daughter Idril.
Meanwhile, Eöl had also come to the gates of Gondolin and was taken captive by the guard. When he identified himself as the husband of Aredhel, all were surprised and sent a messenger to Turgon. Aredhel confirmed that he was her husband and asked Turgon to allow him to be brought into Gondolin for judgment by Turgon. Upon first sight of Gondolin, Eöl was amazed at its splendor and hated the Noldor all the more for it. Turgon, though, treated him as a kinsman and offered him to live in Gondolin, though he would never be permitted to leave, now that he had found his way to the hidden city. Eöl would not acknowledge Turgon’s law or his right to set boundaries of a kingdom, and he demanded that Maeglin return with him. Maeglin, though, had intentions to stay and said nothing.
Again, Turgon offered him the chance to live in Gondolin … or to die there.
Casting a dart that he’d hidden beneath his cloak at Maeglin, he shouted that he chose the second and for his son also. But Aredhel leaped in front of the dart and was struck in the shoulder. Eöl was set in bonds and would appear the next day for the King’s judgment, and Aredhel and Idril pled to Turgon for mercy. But that night, Aredhel died, for the dart had been poisoned, and Turgon found no mercy for Eöl, ordering him to be cast from the walls of Gondolin.
Maeglin stood by and said nothing, and Eöl—angered by his son’s treachery—predicted that Maeglin would realize none of his hopes in Gondolin and would die the same death as his father. Eöl was then cast over the side of the city to his death.
Idril was bothered by this and would never again trust her kinsmen. Maeglin, meanwhile, thrived—a favorite of Turgon—and was eager to learn and had much to teach. He found many rich deposits of metal in the Encircling Mountains and delved it for the benefit of
Still, Maeglin was not content, for he loved Idril, though no one but she perceived it. The Eldar do not wed such near kin and none had ever desired it before, and she saw it as a perversion, a flaw in him. And his unrequited love turned to darkness in his heart, and he lusted for power so that he might have Idril, and amid the bliss of Gondolin, evil took hold.