Six Wild Crowns (Queens of Elben #1)

"As tradition has it, the king of Elben must marry six queens and magically bind each of them to one of the island's palaces or the kingdom will fall. Clever, ambitious Boleyn is determined to be her beloved Henry's favorite queen. She relishes the games at court and the political rivalries with his other wives. Seymour is the opposite--originally sent to Boleyn's court as a reluctant spy and assassin, she ends up catching Henry's eye and is forced into a loveless marriage with the king. But when the two queens become the unlikeliest of things--friends and allies--the balance of power begins to shift. Together, they uncover a dark and deadly truth at the heart of the island's magic. Boleyn and Seymour's only hope of survival rests on uniting all six of the rival queens--but Henry will never let that happen"--