Joan of Valois, Countess of Beaumont

Joan of Valois (; 1304–1363) was the daughter of Charles of Valois and his second wife Catherine I of Courtenay, titular empress of Constantinople.
Half sister to Philip VI of Valois, in around 1320 she married Robert III of Artois, Count of Beaumont-le-Roger and seigneur of Conches. They had five known children:
Robert III of Artois had attempted to recover the title of count of Artois, which had been taken from him by his aunt Mahaut of Artois, but was condemned and exiled in 1331 for making and presenting forged documents in the process of filing against her. Joan of Valois and their children were therefore imprisoned at Château Gaillard by order of her half-brother Philip VI.
In fiction.
Joan is a character in "Les Rois maudits" ("The Accursed Kings"), a series of French historical novels by Maurice Druon. She was portrayed by in the 1972 French miniseries adaptation of the series, and by in the 2005 adaptation.