> The Silmarillion
Eärendil was an Adan of the House of Haladin. He was a son of the second marriage of Men and Elf, Tuor and Idril. He was born in the great Elven city of Gondolin, but soon moved to live with Círdan the Shipwright and it was there that he was infected with the longing for the Sea. He also married Elwing there, the third marriage of Men and Elf. Their sons were Elrond and Elros, the half-elven.
He could not long resist the call of the Sea, and soon took to exploring the great sea Belegaer in his ship Vingilot. When the son of Fëanor razed his home, Elwing came to his ship with the Silmaril they had and used it to gain entrance to the lands of Aman. There he gained the mercy of the Valar who stopped the sons of Fëanor. But since he was a mortal who had walked in the lands of the Valar, he was forbidden to return to Middle-Earth. The closest he came then after was when he guided some of the Edain to the island of Númenor. After this his ship and the Silmaril were set in the sky by Varda as a sign of hope to those oppressed by evil. This star is the one most beloved by the Elves and its light later filled the Phial of Galadriel that helped the ringbearer Frodo on his perilous quest.