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.
House of Courtenay
The House of Bourbon, which acquired the French throne with Henry IV of France, was another cadet branch of the Capetian dynasty. Under the Salic law, males descended in male line from Hugh Capet are princes of the blood – i.e., they have the right to succeed to the French throne in the event that the male line of the royal family and of more senior princes die out. Hence, the then impoverished Capetian House of Courtenay, being agnatic descendants of Louis VI of France, sought to be acknowledged as "princes du sang" (Princes of the Blood Royal) and "cousins to the king," two titles normally reserved for the members of the royal family and prized for the seats at the Royal Council and the Parliament of Paris that they conferred upon its holders. Three Bourbon kings in a row – Henri IV, Louis XIII, and Louis XIV – turned down their petitions. That the Bourbon monarchs confined the French royalty to the descendants of Louis IX is evidenced by the Treaty of Montmartre (1662) which named the non-Capetian House of Lorraine as the next in line to the French throne after the Bourbons, thus bypassing the Courtenay branch, a Capetian family. Although the Courtenays protested against this clause, their claims to the princely title were never acknowledged by the Paris Court of Accounts. The last male member of the French Courtenays died in 1733, but his niece married the Marquis de Bauffremont, and her descendants assumed the title of "Prince de Courtenay" with dubious validity, which they bear to this day. However the marquis de Beauffremont was made on 8 June 1757 Prince of the Holy Roman Empire (inheritable by all male-line descendants); this title was recognised in France. Beauffremont-Courtenay are also princes of Carency and dukes of Beauffremont.