Damar Series by Robin McKinley

Aerin could not remember a time when she had not known the story; she had grown up knowing it. It was the story of her mother, the witchwoman who enspelled the king into marrying her, to get an heir that would rule Damar; and it was told that she turned her face to the wall and died of despair when she found she had borne a daughter instead of a son. Aerin was that daughter... moreAerin could not remember a time when she had not known the story; she had grown up knowing it. It was the story of her mother, the witchwoman who enspelled the king into marrying her, to get an heir that would rule Damar; and it was told that she turned her face to the wall and died of despair when she found she had borne a daughter instead of a son. Aerin was that daughter. But there was more of the story yet to be told; Aerin's destiny was greater than even she had dreamed--for she was to be the true hero who would wield the power of the Blue Sword... less

Harry Crewe is an orphan girl who comes to live in Damar, the desert country shared by the Homelanders and the secretive, magical Hillfolk. Her life is quiet and ordinary-until the night she is kidnapped by Corlath, the Hillfolk King, who takes her deep into the desert. She does not know the Hillfolk language; she does not know why she has been chosen. But Corlath does. Harry is to be trained in the arts of war until she is a match for any of his men... moreHarry Crewe is an orphan girl who comes to live in Damar, the desert country shared by the Homelanders and the secretive, magical Hillfolk. Her life is quiet and ordinary-until the night she is kidnapped by Corlath, the Hillfolk King, who takes her deep into the desert. She does not know the Hillfolk language; she does not know why she has been chosen. But Corlath does. Harry is to be trained in the arts of war until she is a match for any of his men. Does she have the courage to accept her true fate? less