The One-Armed Queen (Great Alta Saga)

The Queen of the Dales, White Jenna, had three children: two boys of her body, Jemson and Corrie, and one daughter, the eldest, Scillia. Scillia was adopted by the Queen in the way of her people, the Warrior Priestesses of the Hames, and Scillia is the heir, destined to rule the Dales when Jenna dies. But the king of Garun-over-the-Sea, a nation that has been at war with the Dales for a generation, cannot believe that an adopted daughter could take precedence over a natural-born son. The Garuns will use every wile to convince Jemson, the eldest boy, to rebel against his mother and sister, and take the throne for his own, weakening the Dales and leaving the land open for a new Garun invasion.