To the King a Daughter (The Cycle of Oak, Yew, Ash, and Rowan)

is book #1 of The Cycle of Oak, Yew, Ash, and Rowan.
==Book Description==
To the King a Daughter begins the cycle of Oak, Yew, Ash, and Rowan: the four powers of the world who have been warring for centuries. The Clan of Ash is slowly dying, their totem tree in the sacred square withering away to nothing. There is a prophecy that a daughter of Ash will rise again, but none have survived the mass killings, thereby rendering the prophecy unfillable.
But deep in the swamps, in the care of the witch-healer all need and all fear, there is a young girl-woman who can not be the witch's daughter; a girl who, in fact, by virtue of her beauty and elegance and simmering power, can only be a Daughter of Ash, the one who will rise to fulfill the prophecy--and the destiny of her birthright.
(Description from amazon.com)