High Lord Elena is a woman that Thomas Covenant meets when he returns to the Land in the second book, The Illearth War. She falls in love with him, though is revealed to actually be his daughter via his rape of Lena.
Shortly after Thomas Covenant raped Lena, she became pregnant with his child. While Elena was growing up Ranyhyn rode into Mithil Stonedown as a result of Covenant's promise with them. Elena rode a Ranyhyn as a child were it took her to the horserite and she drank in the water and began to desire Lord Foul's demise. As High Lord she became fixated by her ancient predecessor Kevin, believing his return to be the only antidote to Lord Foul's evil. In summoning him from the grave she assured her own downfall and enslavement.