Army of the Dead

The Army of the Dead, also known as the Dead Men of Dunharrow or Oathbreakers, were Men of the White Mountains, cursed to remain in Middle-earth by Isildur after they abandoned their oath to aid him in the War of the Last Alliance. They haunted the caverns beneath the Dwimorberg, and the valley of Harrowdale that lay in its shadow, though they were said to appear in the valley only in times of trouble or death. They were led by the King of the Dead, whose name had long been forgotten. Since the line of Isildur was thought to have ended, no one could call upon the Dead Army to aid them in their hours of need, as they would only answer to an Heir of Isildur.
== History ==
They were once Men of the White Mountains, but at the founding of Gondor, they swore an oath to Isildur that they would fight for him. However, during the dark years, they had worshiped Sauron, and so when the time came and Isildur asked for their aid, they refused. And so Isildur cursed them. Therefore, they fled from the wrath of Isildur and dared not go forth to war for Sauron, and they hid in secret places in the mountains and had no dealings with other men. They slowly started to dwindle and the terror of the Sleepless Dead came about to all the places where they lingered.
Malbeth the Seer prophesied that a day would come when need and haste would drive one of Isildur's heirs to take the Road under the Mountain, and that the dead would answer to his call. The Prophecy came true. In the War of the Ring, Isildur's Heir, Aragorn, called on the Dead Men. Summoning them to the Stone of Erech, Aragorn commanded them to fulfill their oath and be free.
Aragorn led the Army of the Dead through Lamedon and Ciril. As they went through the lands of Gondor, they found them deserted, since everyone who hadn't gone to war fled the approach of the dreaded "King of the Dead". Even the men of Umbar and Harad, who had been attacking the fords at Linhir above the mouth of the river Gilrain, stopped fighting and ran off in terror. The only person who had the courage to stay was Angbor, the Lord of Lamedon, and Aragorn told him to gather his men and follow the Grey Company to Pelargir. For four days and nights after Aragorn first summoned the dead to the Stone of Erech, they rode.
On the fifth day they reached their destination (Pelargir), where the main fleet of Umbar was assembled. Some of the ships had set sail for Minas Tirith already because rumor of the dead army had reached the havens. In spite of these rumors, however, the Haradrim whom the Company had been pursuing turned at bay and laughed, seeing only Aragorn and his host of live Dunedain warriors, as the dead were hanging back behind them to surprise their foes. Aragorn then called to the Army of the Dead to fight, which resulted in a bloody battle. Despite not needing weapons, the weapons of the Enemy could not harm them.
The Army of the Dead attacked first the ships that were still anchored, and then walked over the water to the ones that had set sail. The terrified Corsairs abandoned their ships and jumped overboard; all either drowned or headed south back to their homelands. Once the Haradrim and Corsairs were defeated, Aragorn had trumpets sounded and the dead withdrew to the shore. As they had at last fulfilled their oath, Aragorn granted the Dead Army their freedom. The King of the Dead stepped forward, broke and discarded his spear; he bowed to Aragorn, and with the Army vanished at last from the world.