Based on a true event from 16th century Spain, this costume drama follows the tragic life of Ana de Mendoza, Princess of Eboli, (Olivia de Havilland) who is secretly loved by her good friend the King. Unfortunately for the monarch, she marries one of his ministers and bears his son. Her husband eventually dies and later the King asks her help train a replacement for her late husband. When romantic sparks begin flying between the woman and her protege, the king becomes terribly jealous and this sets in motion a terrible tragedy.