Isabella of Aragon, Queen of France

Isabella was the eighth child and youngest daughter of King James I of Aragon[3] and his second wife Violant of Hungary.[4] Her exact date of birth wasn't recorded, but she certainly was born in late 1247 or early 1248, because her father, who financially supported the Monastery of Santa María de Sigena, stipulates in his will dated in January 1248 that if he had another son, he should become a knight Templar and if the child was a daughter, she should enter at Santa María de Sigena as a nun. The will certainly was abandoned before Isabella's birth because she was married.[5][6]

On 11 May 1258, was concluded the Treaty of Corbeil between the Kings Louis IX of France and James I of Aragon; as a part of the agreement was arranged the betrothal between the French prince Philip —second son of Louis IX— and Isabella —youngest daughter of James I—.[7] The formal wedding took place on 28 May 1262 at the city of Clairmont (currently Clermont-Ferrand); at the time, Prince Philip was already the heir of the French throne after the death of his older brother Louis in 1260. The union produced four sons:

1. Louis (1264 –1276), heir of the French throne from 1270 until his death.
2. Philip IV "the Fair" (1268 –1314), King of France
3. Robert (1269 –1271).
4. Charles, Count of Valois (1270 –1325).

Having accompanied her husband and father-in-law to the Eighth Crusade against Tunis in July 1270, Isabella became Queen consort of France the following month on the death of King Louis IX. On their way home, while crossing the Savuto river near Martirano in Calabria, on 11 January 1271 she suffered a fall from her horse: six months pregnant with her fifth child, she gave birth prematurely a son, who died soon after. First transported to Martirano Castle and then to Cosenza, exhausted and feverish, Isabella died there on 28 January 1271 aged 24. Her death was a devastating emotional blow to her husband, especially since she had been pregnant.

Because she died far from her homeland, the funeral technique of Mos Teutonicus was practiced upon Isabella.[8] Firstly, she was buried at Cosenza Cathedral alongside her newborn son,[9] and then in the royal necropolis in the Basilica of St Denis.[8] Isabella's tomb, like many others, was desecrated during the French Revolution in August 1793.

The tragic end of Isabella is recalled in the Laudi of the poet Gabriele D'Annunzio.

• Rodrigo Estevan, María Luz (2009). "Los testamentos de Jaime I: Repartos territoriales y turbulencias políticas". Cuadernos, Centro de Estudios de Monzón y Cinca Media (in Spanish) (35): 61–90. ISSN 1133-3790.
• Zurita, Jerónimo. José Javier Iso; María Isabel Yagüe; Pilar Rivero (eds.). Anales de Aragón (PDF) (in Spanish). Exma. Diputación de Zaragoza, «Institución Fernando el Católico».