One-armed Queen

A realm of women and magic, The Dales was ruled by the Queen called White Jenna, a great warrior with a mystic second self: her dark sister, Skada, who stepped from the shadows to speak the truths that others dared not say.
But the kingdom of Garun-over-the-Sea, ruled by cruel, fearful men who could not tolerate a country ruled by a woman and a Goddess, declared war on the Dales. Jenna, with her beloved consort, Carum, by her side, waged a great battle and won, bringing peace once again to the land.
An ancient prophecy of the Dales foretold that Jenna would one day find a child who was, like herself, the daughter of three mothers, and proclaim the girl her heir. And, on the field of battle, Jenna received a one-armed girl named Scillia from her dying mother's arms, and adopted the baby as her own daughter. Scillia was named heir to the throne.
But when Scillia came of age, she discovered the truth her mother had long concealed from her, and a great rift opened between them, a rift which the men of Garun will exploit to take by stealth what they could not win in battle.