Eärendil

Eärendil (Quenya; IPA: [e.aˈrendil]) was a great Half-elf mariner who voyaged to Valinor, entreated before the Valar on behalf of the Children of Ilúvatar, and carried a star across the sky at the end of the First Age. His acts had been prophesied of among the Elves centuries beforehand.
He was the father of Elros, the first King of Númenor, and of Elrond, the Lord of Rivendell and an important figure in the Second and Third Ages.

Eärendil was the first, seminal character of J.R.R. Tolkien's mythology; his name and purpose as a character were inspired by an excerpt of Cynewulf that Tolkien found in the poem Crist. Eärendil's story is found in The Silmarillion, but he is invoked and referred to by many characters throughout The Lord of the Rings.