Lord of the Dark Tower

During the First Age, Sauron had been the lieutenant of Morgoth, the most trusted and powerful of the servants of the first Dark Lord. After the fall of Morgoth and the ending of the First Age, Sauron concealed himself in Middle-earth for centuries. Observing the growing power of the Númenóreans as the Second Age passed, Sauron saw the need to establish a secure base of power for himself. He chose the mountain-walled land that became known as Mordor, and there he exerted his power in the construction of an immense, impregnable stronghold. This stronghold became known as Barad-dûr, the Dark Tower of Mordor, and from that time (the Dark Tower was completed in about II 1600) Sauron was titled the Lord of Barad-dûr or - rather more rarely - the Lord of the Dark Tower.

From the time of its completion, Sauron ruled from his Dark Tower for nearly 1,700 years in the Second Age, overrunning much of Middle-earth during this time, especially the lands to the East. In II 3262 the Númenóreans brought an immense fleet to Middle-earth, and even Sauron could not withstand their might. Instead he abandoned his Dark Tower for a time, willingly submitting to King Ar-Pharazôn and working to subvert him to the worship of Morgoth. Sauron's scheming in this time brought about the Downfall of Númenor, but Sauron himself escaped the fall of the island kingdom and returned across the Sea to the Dark Tower.

At the same time as Sauron's return, the new kingdoms of Arnor and Gondor had been established in Middle-earth by his enemies, Númenórean survivors of the Downfall he had engineered. Sauron made war on these Kingdoms of the Dúnedain, capturing the Gondorian tower of Minas Ithil and investing the city of Osgiliath, but his actions brought dire consequences down on him. A great Alliance of Elves and Men descended on him from the North, driving him back to his Dark Tower and, after a long Siege, seeing his physical form destroyed.

As the Third Age drew on, Sauron was eventually able to take control once more of the dark things of Middle-earth, but for a long time he avoided the ruins of the Dark Tower, now closely guarded by his enemies. Over the passage of centuries, that guard waned and failed, and in III 2942 Sauron at last returned to Mordor, beginning the rebuilding of the Barad-dûr nine years later. Now he was once again the Lord of the Dark Tower, and remained so through the period known as the War of the Ring in opposition to the White Tower of Minas Tirith. His rule finally came to an end in III 3019, when the destruction of the One Ring caused Sauron's ultimate downfall. With the unmaking of the Ring, the power sustaining the foundations of the Barad-dûr also failed, and so not only did the Lord of the Dark Tower meet his end, but the Tower itself was utterly destroyed.