Overview
Blanche of Valois (baptised Marguerite; 1317–1348) was Queen of Germany and Bohemia by her marriage to King and later Holy Roman Emperor Charles IV. She was the youngest daughter of Charles of Valois and his third wife Mahaut of Châtillon.
Early life
Blanche grew up at the French court of her cousin Charles IV of France, who was a nephew to her father. She spent much time with Charles' wife Marie, who was an aunt to her future husband.
A betrothal between Blanche and Charles, eldest son of John of Bohemia was contracted in 1323. Charles had been staying at the French court as he had been sent by his father to be educated; he had been baptised Wenceslaus but changed his name upon the betrothal in honour of King Charles.
The importance of Blanche's position grew when King Charles died without male heirs and so Blanche's brother succeeded as Philip VI of France. He had his son and heir John betrothed and later married to Charles' sister, Jutta.
From Wikipedia (CC BY-SA 4.0).