Sauron the Cruel, the first and the chief apprentice of the Dark Lord Melkor. He was his lieutenant in the First Age and governed the fortress of Minas-Morgul on the island Tol-in-Ghaurhot. There died King Felagund with his ten companions. But Sauron himself was defeated by an elven-maiden Luthien, who came to save her beloved, Beren. I think he may have also looked like this when he came among the Elves of Eregion, in the Second Age.