Isabelle of France was a 13th-century princess and daughter of King Louis VIII and Blanche of Castile. Despite being betrothed to Hugh of Lusignan and pressured to marry Conrad IV of Germany, she remained committed to a life of virginity. She established the monastery of Longchamp near Paris, creating a unique rule for the community with the help of Franciscan scholars. Although she lived as a patroness rather than a formal nun due to health issues, she dedicated her life to religious devotion and supporting the poor.