Eowyn was the golden-haired and grey-eyed daughter of Eomund and Theodwyn. Her uncle (Theodwyn'a brother) was Theoden, King of Rohan, and she had one sibling, a brother called Eomer. Eowyn was very young when her father died, slain by Orcs, and her mother died of grief shortly afterwards. It was then that Eowyn and Eomer were brought to Edoras to be cared for by Theoden. Soon a man called Grima (who was commonly known as Wormtongue) arrived in Edoras. His eyes immediately turned to Eowyn, whom he was captivated by. Grima became a counsellor of the King, but was secretly working for the triator Saruman, who was the head of the White Council. In reward for his services, Saruman said that when Rohan was destroyed, Eowyn would be handed to Grima for his wife. But Eowyn despised Grima, for she knew it was his words that poisoned her uncle's mind and had forced her country into near ruin.
Soon Aragorn, son of Arathorn arrived in Rohan with his companions, and Eowyn quickly fell in love with him. But it was not to be, as Aragorn was already betrothed to another. She begged Aragorn to let her ride with him to the Paths of the Dead, but Aragorn did not allow her to. After he left, Eowyn was stricken with grief at his supposed death, and rode into battle disguised as a soldier called Dernhelm; she took with her the hobbit Meriadoc Brandybuck. During the battle, Theoden stood against the Witchking of Angmar, the Lord of the Nazgul, who was seated upon his terrible fell beast flying stead. Theoden became mortally wounded, and as his soldiers fled from the fell beast the the Witchking, one did not. This was Eowyn. She revealed herself as 'no living man', and hewed the head of the flying best off. Then, with the help of Meriadoc, she slew the Witchking himself, gaining the greatest renown of any warrior.
But Eowyn fell under the poisoned Black Breath of the Witchking, and was found by her brother Eomer, who, thinking her dead, despaired. He bade her be taken into Minas Tirith along with Theoden. But on the way, Prince Imrahil of Dol Amroth saw her and realised she was not dead. She was then taken into the Houses of Healing, where she was healed by Aragorn with the help of the athelas herb. She remained in the Houses of Healing until after Sauron was defeated. While there she met Faramir, the son of Denethor who had been Steward of Gondor, and he fell in love with her. Soon she returned his love, and the couple married. Eowyn gave up being a shiedmaiden and decided to become a healer. After the coronation of King Elessar (Aragorn), she nad Faramir lived in Ithilien and she became known as the White Lady of Ithilien.
They had one son, called Elboron. Her date of death is not known.
In the films she is played by Miranda Otto.