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.
Fils de France
Although the children of monarchs are often referred to in English as "prince" or "princess", those terms were used as general descriptions for royalty in France but not as titular prefixes or direct forms of address for individuals (with the exception of "Monsieur le Prince" for the senior "prince du sang") prior to the July Monarchy (1830–1848). Collectively, the legitimate children of the kings and dauphins were known as "enfants de France" ("children of France"), while examples abound in reputable works of "fils de France" and "fille de France" being converted into other languages as "Prince/Princess of France" (however the same works, as cited, leave the Spanish equivalent, "Infante/Infanta de España)", untranslated. The illegitimate children of French kings, dauphins, and "princes du sang" were not entitled to any rights or styles "per se", but often they were legitimised by their fathers. Even then, however, they were never elevated to the rank of "fils de France", although they were sometimes accorded the lower rank and/or privileges associated with the "princes du sang".