Éomer was the nephew and adopted son of King Théoden Ednew of Rohan. Upon Theoden's death in T.A. 3019, he became the eighteenth King of Rohan, and the first of the Third Line. He ruled until F.A. 63, orchestrating Rohan's growth throughout an era of unprecedented peace and prosperity. Éomer was born in Edoras in T.A. 2991. His father, Éomund, was Chief Marshall of the Mark until he was ambushed and slain by Orcs in T.A. 3002. Since Éomer's mother, Théodwyn, died of grief in the King's household soon afterwards, King Theoden adopted the eleven year-old boy and his older sister Éowyn. Éomer was groomed for a position of great honor and responsibility and received the finest training available to the Horse-lords of the Riddermark, but Prince Théodred was Theoden' s sole true son and therefor