The sons of Fëanor learning of the dwelling of Elwing and the Nauglafring [on which was set the Silmaril of Beren] had come down on the people of Gondolin. In a battle all the sons of Fëanor save Maidros and Maglor were slain, but the last folk of Gondolin were destroyed or forced to go away and join the people of Maidros. Maglor sat and sang by the sea in repentance. Elwing cast the Nauglafring into the sea and leapt after it, but was changed into a white sea-bird by Ylmir, and flew to seek Eärendel, seeking about all the shores of the world.
