Louis Alphonse, Duke of Anjou
Their father has conferred upon them the historic French titles of, respectively, Duke of Burgundy ("duc de Bourgogne"), and Duke of Berry ("duc de Berry"). (In Spain, the twins are "Don" Luis and "Don" Alfonso de Borbón Vargas). Prince Louis, as Legitimist Dauphin of France, is expected to succeed his father as head of the French royal house, the senior Bourbon/Capetian line, in Legitimist reckoning. However, under Spanish law, and assuming Felipe VI does not in future father a son, the Spanish crown will be inherited by his elder daughter Leonor, Princess of Asturias, who will become queen regnant, and if Felipe does have a son, that son will inherit the Spanish throne regardless of the genealogical seniority of the Anjou branch. Louis and Alphonse were baptised on 5 September 2010 at St Peter's Basilica in Vatican City. Louis' godparents were Arancha Martínez-Bordíu and Francisco D'Agostino and Alphonse's were Amparo Corell de Trenor, and Lorenzo Perales.
Dauphin of France
The title was abolished by the Constitution of 1791, which made France a constitutional monarchy. Under the constitution the heir-apparent to the throne (Dauphin Louis-Charles at that time) was restyled "Prince Royal" (a "Prince of the Blood" retitled "prince français"), taking effect from the inception of the Legislative Assembly on 1 October 1791. The title was restored "in potentia" under the Bourbon Restoration of Louis XVIII, but there would not be another Dauphin until after his death. With the accession of his brother Charles X, Charles' son and heir Louis-Antoine, Duke of Angoulême automatically became Dauphin.