These Old Shades is a 1926 historical romance written by British novelist Georgette Heyer. The novel is set around 1755: Heyer refers to the Duke of Avon's participation in the 1745 uprising as ten years previous; in addition the Prince of Condé is said to be about 20 years old. However, she also refers to Madame de Pompadour as actively involved with Louis XV, whereas her relationship with the King ended at about 1750. Source: Wikipedia (en)