Could Harry and Meghan's daughter become Duchess of Sussex?

[septimus]

@Northern_Piper

Not necessarily, in Britain…

One of Nelson’s peerages is an example. He was created Baron Nelson twice, as well as Viscount Nelson. The first barony and the viscounty both were granted to him with succession to his male heirs, in the normal way. Since he never had male heirs, those titles went extinct on his death.
[But] the second barony had an unusual line of descent. If Nelson died without a male heir, it went to his father, followed by his father’s other son and that son’s male heirs. If that other son had no male heirs, it went to the male issue of Nelson’s elder sister, followed by the male issue of his second sister.

Yes, thank you. I should have written “almost always.”

Ironically I made the same observation about the Earls Nelson six month ago:

@septimus

Nitpick: The present Earl Nelson is not a descendant of the famous Admiral Horatio Nelson (who had no legitimate children), nor even of the 1st Earl Nelson (Horatio’s brother William, whose legitimate issue also went extinct). Instead he is a descendant of the 2nd Earl, Thomas Bolton (nephew of Horatio and William), who changed his surname to ‘Nelson’ when he was earled.

Allowing an Earldom to be inherited by a brother, let alone via a sister, was a special favor, but no posthumous honour was too great for the man who won the Battle of Trafalgar. The same special remainder was specified when the Admiral was given his 2nd Barony in 1801, after winning the Battle of Copenhagen. Thus the 6th Earl Nelson of Trafalgar and of Merton was also the 7th Baron Nelson of the Nile and of Hilborough.

This still leaves my question unanswered. Why did almost all the Counties of Western Europe follow Salic inheritance, while several Kingdoms (and French Duchies?) followed cognatic primogeniture?