Duchess of Anjou
Source (Wikipedia): Yolande of Aragon

Yolande of Aragon was Duchess of Anjou and Countess of Provence by marriage, who acted as regent of Provence during the minority of her son. Yolande played a crucial role in the struggles between France and England, influencing events such as the financing of Joan of Arc’s army in 1429 that helped tip the balance in favour of the French. She was also known as Yolanda de Aragón and Violant d’Aragó. Tradition holds that she commissioned the famous Rohan Hours.