Inspired by the visit of the Pope I have been looking at the Jacobite Succession, which is the Catholic line through which the crown in pretence of England and Scotland has descended since the flight of James II & VII from London at the time of the Glorious Revolution.
A particular highlight is Henry Benedict Stuart (11 March 1725 – 13 July 1807) the younger brother of Bonnie Prince Charlie who was, handily, one of the longest ever serving Roman Catholic Cardinals, as well as the fourth and final Jacobite heir publicly to claim the thrones of England, Scotland, and Ireland.
In his youth, Henry's father made him Duke of York (in the Jacobite peerage), and it was by this title that he was best known. Upon the death of his brother in 1788 Henry became known by Jacobites, and within his personal entourage, as Henry IX of England.
Notably, the Cardinal-Duke of York was the last claimant to the English throne to touch for the King's Evil. That is to attempt to cure, say, tuberculosis by divine right through by laying on of hands.
Eat your heart out, Umberto Eco.