Éowyn is a daughter of the House of Eorl and the niece of King Théoden of Rohan. Éowyn was born in T.A. 2995 as the daughter of Éomund and Théodwyn, youngest sister of the King. Éowyn's elder brother was Éomer, who was four years older than her. She was orphaned at the age of seven after her father was killed by Orcs, and her mother died soon after. She and her brother were taken in by their uncle. Éowyn cared for Théoden while his thoughts were poisoned by his advisor Gríma, a spy of Saruman.
During the War of the Ring she was given temporary leadership of her people while the King and his warriors went to war at Helm's Deep. She led her people to the safe Dunharrow in the White Mountains, where the people stayed during the remainder of the War. After returning from Isengard the army of Rohirrim made a short stay in Dunharrow, before being summoned to aid Gondor. Hopeless as to the outcome of the War, Éowyn went with the Rohirrim under the guise of Dernhelm. She offered to let Merry to ride with her, and he accepted although he did not recognize who she was. As such she fought at the Battle of the Pelennor Fields. There she confronted the Witch-king of Angmar, leader of the Nazgûl. With Merry's help, she managed to kill the Witch-king. Merry struck the Witch-king with his Dúnedain blade forged for use against the forces of Angmar, which enabled Éowyn to make the fatal stroke. This fit with a thousand year old foretelling, that the Witch-king would not be killed "by the hand of man": Éowyn was a woman, and Merry a Hobbit. During the fight her arm was broken, earning her the title Lady of the Shield-arm.
During her stay in the Houses of Healing in Minas Tirith, she met Faramir and fell in love with him. They were later that year married in Edoras, after which they went to live in Emyn Arnen as the Lord and Lady of Ithilien. The couple had at least one son, Elboron, and one grandson, Barahir.
Reception and Opinions
Éowyn, like the hobbits Pippin and Merry, disobeyed higher authority. She risked censure or punishment for going on a quest, and yet proved in a crucial moment that she did well thereby. If the Council had not allowed Merry and Pippin to join the other Seven Travellers, who would have roused Treebeard? And Pippin saved Faramir from a fiery death at the hands of his grief-crazed father.
Éowyn is the most heroic female character in The Lord of the Rings. Loyally taking care of the king (her uncle), she noted with dismay how Wormtongue (a spy for Saruman) seduced Theoden into acting the dotard. Her spirit was roused by the arrival of Aragorn, and she demonstrated the utmost loyalty to king and country by disguising herself as a man and riding with Merry into battle, where fortuitously she and Merry were able to unseat the leader of the nine Black Riders, turning the tide of the battle.
- She came to an understanding with Elfhelm about Merry and the Marshal and his Riders ignored the Hobbit's presence. If Elfhelm recognized Dernhelm to be Éowyn, he said nothing about it to the King. Éowyn spoke to no one else in the company. 
In Peter Jackson's film adaptations of The Lord of the Rings, Éowyn is played by the Australian actress Miranda Otto. Although Éowyn is by far the most important female character in the book, Peter Jackson's adaptation carves out a significant role for Arwen, played by Liv Tyler.
- 'But to some one I must now entrust my people that I leave behind, to rule them in my place.' [...] 'She is fearless and high-hearted. All love her. Let her be as lord to the Eorlingas, while we are gone.' 'It shall be so,' said Theoden. 'Let the heralds announce to the folk that the Lady Éowyn will lead them!' - J. R. R. Tolkien, The Lord of the Rings, Book III, Chapter 6 "The King of the Golden Hall".
- "He caught the glint of clear grey eyes; and then he shivered, for it came suddenly to him that it was the face of one without hope who goes in search of death." - J. R. R. Tolkien, The Lord of the Rings, Book V, Chapter 3 "The Muster of Rohan".
- "For into Merry's mind flashed the memory of the face that he saw at the riding from Dunharrow: the face of one that goes seeking death, having no hope." - J. R. R. Tolkien, The Lord of the Rings, Book V, Chapter 6 "The Battle of the Pelennor Fields".
- "There seemed to be some understanding between Dernhelm and Elfhelm, the Marshal who commanded the éored in which they were riding. He and all his men ignored Merry and pretended not to hear if he spoke. He might have been just another bag that Dernhelm was carrying. Dernhelm was no comfort: he never spoke to anyone." - J. R. R. Tolkien, The Lord of the Rings, Book V, Chapter 5 "The Ride of the Rohirrim".
- '...the Witch-king turned to flight and passed into the shadows. [...] but Glorfindel, looking into the gathering dark, said: "Do not pursue him! He will not return to this land. Far off yet is his doom, and not by the hand of man will he fall."' - J. R. R. Tolkien, The Lord of the Rings, Appendix A, I, iv Gondor and the Heirs of Anárion