Its creation is not considered part of the illegitimate Jacobite peerage, and no Writ of attainder was issued by Parliament for the Dukedom (although it was for the Duke himself), the title is still considered by some as theoretically extant, albeit dormant, in the Peerage of England and could be petitioned for reinstatement by the legitimate heirs male of the body (as detailed below in the list of Jacobite succession).

However, unlike the English peerage, the Spanish title follows the rule of absolute primogeniture, which allows a female to succeed if she is the first-born child.

The heir presumptive to the Dukedom is the 12th Duke’s younger brother Don Luis Fitz-James Stuart y Gómez, 14th Marquess of Valderrábano (born 1950).

The peerage and its subsidiary titles were generally considered to have been forfeit by the English parliament in 1695, when James FitzJames was attainted following the enforced exile of his father.

With her death in November 2014, the dukedom passed to her eldest son, Don Carlos Fitz-James Stuart y Martínez de Irujo.