Savage Winter (Seasons of Paleo Book 1) by Rachel Van Dyken

If they take you, you don’t come back. You either die…or wish you had. The Western Empire was ruthless. The only reason I survived was because he gave his life for me–a life that might as well have been mine, for when they stole his last heartbeats, they silenced my own. They call me princess, an answer to the prophecy, but I’m nothing more than a prisoner…awaiting my lifelong punishment. Marriage. To the Prince of the East. But it’s the Royal Protector who reminds me of what I lost. He threatens something I never thought I’d have again…my heart.