The author of numerous studies on the history of France, laureate of the Grand Prize of Paris in 1982, member of the French School in Rome and the House of Velazquez in Madrid, Ivan Clulas, with great success, introduces the reader to the era of the last Valois. He brilliantly and vividly reveals the image of the most incredible woman of the 16th century, the favorite of King Henry II - Diana de Poitiers, Duchess of Valentinois. At the age of eleven, Henry falls in love with the twenty-nine-year-old beauty Diana, and when she turns 48, he makes her Duchess de Valentinois and gives the palace to Ana. Were her contemporaries right when they claimed that she won the king’s heart not so much with her beauty as with the advice she gave him and her love for art, which she was well versed in? Ivan Clulas offers his explanation of the mystery of Diane de Poitiers' charm.