Aragorn is a Ranger of the North, first introduced with the name Strider and later revealed to be the heir of Isildur, an ancient King of Arnor and Gondor. Aragorn is a confidant of the wizard Gandalf and plays a part in the quest to destroy the One Ring and defeat the Dark Lord Sauron. As a young man, Aragorn falls in love with the immortal elf Arwen, as told in "The Tale of Aragorn and Arwen". Arwen's father, Elrond Half-elven, forbids them to marry unless Aragorn becomes King of both Arnor and Gondor.