Moria, or Khazad-dum, is a Dwarven underground city beneath the Misty Mountains. For thousands of years, a thriving Dwarvish community had delved deep below the mountains seeking to build their lives there, to find treasure like Gold and Mithril. Mithril was only ever found and mined in Moria, no other Dwarven mountain held Mithril within. Moria was abandoned during the Third Age after Dwarves went too deep and awoke a Balrog of Morgoth. None dared take back the mountain in fear of the Balrog for centuries. Later there was an expedition led by Balin, Oin, and Ori to attempt to reclaim Moria. The Dwarves were successful in entering the mountain and rebuilding a home for many years, but then Orcs came to overthrow Moria. The main gates were overrun as countless Orcs flooded in and hall by hall took control of Moria. The last surviving Dwarves took shelter in one of the tombs and made their last stand as Orcs broke through the door like a hole in a dam. Moria was controlled by Orcs for many years, there were no more expeditions to retake the mountain. Later in the Third Age, The Fellowship of the Ring could not go over the mountain, so the only other option was to go through it, through Moria. Only a few in the Fellowship knew that Moria was overrun, but the other had still thought Dwarves controlled it. The Fellowship quickly realized Moria was not under Dwarven control and made their way to the Tomb, the same one that the Dwarves made their last stand. Like the Dwarves, The Fellowship had to make a stand in the Tomb, but held off the Orcs long enough for a short break to make a run for it. They fled to the center hall until the Balrog awoke, they then made their way to the Bridge of Khazad-dum. The Balrog caught up with The Fellowship by the time they got to the bridge, and there Gandalf made his last stand against the great demon while The Fellowship fled to exit. Gandalf and the Balrog fell as the bridge was destroyed and Gandalf, after a long battle, killed the Balrog and went to the Heavens. But he was sent back, his task was not complete and the Ring still survived, and so does Sauron, so Gandalf is to stay in Middle-Earth until the Ring is destroyed and The Free Peoples of Middle-Earth are saved. Later another expedition was led into Moria and finally drove the Orcs away and Moria was again under Dwarven Control.