Line of succession to the former throne of the Two Sicilies

The Kingdom of the Two Sicilies was unified with the Kingdom of Italy in 1860. The headship of the House of Bourbon-Two Sicilies has been disputed since the death of claimant Prince Ferdinand Pius, Duke of Calabria on 7 January 1960 between Infante Alfonso, Duke of Calabria and his descendants and Prince Ranieri, Duke of Castro and his descendants. The two current claimants to the former realm of the Two Sicilies are Prince Pedro, Duke of Calabria and Prince Carlo, Duke of Castro, both descended in the male line from Charles III of Spain, who succeeded to the crowns of Naples and Sicily in 1734, reigning there until his succession to the throne of Spain with the death of his brother, Ferdinand VI of Spain on 10 August 1759. By the treaties of Vienna of 1738 and Naples of 1759 he was obliged to surrender the thrones of Naples and Sicily to preserve the European balance of power,

The treaties of Vienna and Naples required that King Charles separate the Spanish crown from the Italian sovereignties by designating Don Charles, his second surviving son (the eldest being severely mentally handicapped), as Prince of Asturias, the heir apparent to Spain, while his "Italian sovereignty" would pass immediately to his third son and his descendants in the male line, Infante Don Ferdinand, and then, in the event of the death of the latter without male heirs, to Charles's younger sons and their descendants, by primogeniture. This new semi-Salic, succession law of the defunct Kingdom of the Two Sicilies was laid out by Charles III in the Pragmatic Decree of 6 October 1759, and established a secondogeniture similar to that governing the successions to Tuscany and Modena in the House of Austria. It further stipulated that heirs male of the body of Charles III or, failing males, the female nearest in kinship to the last male in his descent or, that lineage also failing, the heirs male of Charles III's brothers, would inherit the Italian sovereignty (which meant the kingdoms of Naples and Sicily) but always separate from the Spanish crown and never combined in the same person. Should the male line descended from Charles III's younger sons fail, the Italian Sovereignty was always to be transferred to the next male dynast in the order of succession who was neither the monarch of Spain nor his declared heir, the Prince of Asturias. Even if Infante Alfonso, Duke of Calabria, whose mother was Princess of Asturias had inherited the Spanish Crown and if he had then succeeded in 1960 as head of the Two Sicilies Royal House, the Pragmatic Decree of 1759 would have still not applied as it refers to the Italian sovereignty and was designed to preserve the balance of power, a concept that no longer existed in the twentieth century.

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Wikipedia