 Mary and Catherine gained another sibling, Jadwiga, in 1374.Since Louis had fathered no sons, the expectation that he would bequeath Hungary, Poland, and his claims to the Kingdom of Naples and Provence to his daughters made them desirable spouses for members of the European royal families.Before Mary's first birthday, her father made a promise to Charles IV, Holy Roman Emperor, that Mary would marry the emperor's second son, Sigismund of Luxembourg.