Beren and Lúthien are the central characters in chapter nineteen of J.R.R. Tolkien's The Silmarillion.
Brief summary:
Beren's this guy who spends his days wandering around in the woods, killing orcs and such. One day he meets Lúthien, who's quite the hottie elf babe. They fall in love but Beren has to recover a silmaril from Morgoth before he can marry her. With her help, he gets it, losing a hand and temporarily dying in the process. They wed and have a son. The end.