BL. ISABELLA OF FRANCE. — Daughter of Louis VIII and Blanche of Castile, sovereigns of France, born in March 1225 and died on 23 February 1270. After refusing advantageous marriage offers, with the help of her brother St. Louis IX she founded in 1259–59 the monastery of the Poor Clares at Longchamp, whose statutes were approved by Alexander IV in 1259 and modified by Urban IV in 1263. Her cult, approved by Leo X in 1521, was extended to the Franciscan Order by Innocent XII in 1696.
Bibl.: Acta SS. Augusti, VI, Paris 1868, pp. 787–808; H. Sbarale, Bullarium Franciscanum, II, Rome 1761, pp. 477–486; III, ibid. 1765, pp. 64–69; L. Duchesne, Histoire de l'abbaye royale de Longchamp 1253–1789, 2nd ed., Paris 1904.