The Dragon and the Jewel by Virginia Henley

With her sapphire eyes and silken dark hair, Princess Eleanor was a bewitching beauty made for a man’s pleasure. Once a child bride, but widowed at a tender age, she swore never to marry again and took a vow of eternal chastity…until Simon de Montfort marched into England and set his smoldering dark gaze upon her, King Henry’s youngest sister, the royal family’s most precious jewel. Bold, arrogant, and invincible, the towering Norman knight inspired awe in the bravest of men…and a reckless desire in Eleanor’s untried heart.