The Last Tudor by Philippa Gregory

Jane Grey was Queen of England for nine days. Using her position as cousin to the deceased king, her father and his conspirators put her on the throne ahead of the king’s half-sister Mary, who quickly mustered an army, claimed her crown and locked Jane in the Tower. When Jane refused to betray her Protestant faith, Mary sent her to the executioner’s block. There Jane turned her father’s greedy, failed grab for power into her own brave and tragic martyrdom.

‘Learn you to die’ is the advice that Jane gives in a letter to her younger sister Katherine, who has no intention of dying. She intends to enjoy her beauty and her youth and find love. But her lineage makes her a threat to the insecure and infertile Queen Mary and, when Mary dies, to her sister Queen Elizabeth, who will never allow Katherine to marry and produce a potential royal heir before she does. So when Katherine’s secret marriage is revealed by her pregnancy, she too must go to the Tower.