Born in 2871 3A, he was a Black Númenórean who lived in the land of Mordor during the Third Age. He and the Black Númenóreans had established their dwellings in Middle-earth during the years of Sauron's domination and worshiped him. He entered the service of the Dark Tower when it first rose again (its rebuilding began in 2951 of the Third Age), and through cunning grew to power under Sauron and learned great sorcery.
On December 5, 3001 3A, he was well over 130 years old and briefly appeared in person when he haggled with the armies of the Free Alliance in front of the Black Gate. He briefly insulted the host, asking who had authority to treat with him, and dismissed Aragorn's claim as King. He tried to convince the future king and the wizard Gandalf to give up and let his master win the battle for Middle-earth. Had the plans of Sauron succeeded, he would have become the new lord of Isengard, replacing Saruman after his death.
When Gandalf told him that Sauron's reign is ending, he felt angered by his words but he smiles again and throws Frodo's mithril vest in front of them and says how Frodo suffered before dying. It lets a tear out of Gandalf's eye and the Dark Numenor smiles but Aragorn rides towards him. After saying that takes more than a broken Elvish blade to be a king, Aragorn suddenly draws Anduril and beheads him to everyone's disgust.