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.
Prince du sang
In theory, the princes of the blood included all members of the Capetian dynasty. In practice, only the agnatic descendants of Saint Louis IX, such as the Valois and the Bourbons, were acknowledged as "princes du sang". France's kings, for instance, refused to recognize the Courtenay Capetians as princes of the blood. The Courtenays descended in legitimate male-line from King Louis VI, but had become impoverished, minor nobles over the centuries. Their repeated petitions for recognition to the Bourbon rulers were in vain. When the Treaty of Montmartre was concluded in 1662, declaring the House of Lorraine to be heirs to the French throne in the event of extinction of the Bourbons, the Courtenays protested, requesting substitution of the phrase "the royal house issued in legitimate male line from the kings of France" to no avail. In 1715 Louis-Charles de Courtenay, his son Charles-Roger and his brother Roger were once again rebuffed in their attempt to seek recognition of their status. Roger, "abbé" de Courtenay, was the last male of the family, dying on 5 May 1733, and his sister Hélène de Courtenay, marquise de Bauffremont (1689–20 June 1768), obtained no redress when she appealed to the king in 1737 after the Parlement of Paris ordered the term "princesse du sang royal de France" deleted from court documents.