Black Master

A title used of Sauron by Isildur son of Elendil. His use of the word 'Master' was a reference to Sauron during the Dark Years of the Second Age, during which many of the Men of Middle-earth had worshipped Sauron as a god. Among these were the Men of the Mountains, who had sworn to aid Isildur in the War of the Last Alliance, but who abandoned their oaths rather than incur the wrath of their ancient lord. It was because of this that Isildur cursed them to wander the Paths of the Dead, and so their ghosts remained among the White Mountains throughout the Third Age until they finally fulfilled their oaths and were released by Isildur's distant descendant Aragorn.