house of hurin of emyn arnen revisited
 

Back after a very long time, but still with the same question bugging me, a question that re-emerged after having re-read LOTR recently: years ago I posted a thread on the descent of the house of stewards and their supposed royal blood (as quoted in the post below, Hurin is said to be ultimately of not only high Numenorean descent but also of royal blood):

http://forum.barrowdowns.com/showthread.php?t=12358

Now, whilst this did clarify some issues, I a curious about the following: seen the fact that progeny is scarce amongst those with Numenorean descent, and even more so in the case of the royal family, I was wondering whether one cannot pinpoint the descent of this house to certain specific individuals in the line of Elros, but before Numenor was destroyed.

I don't know how cannonical this pdf is, but it might be helpful for a start:
http://lalaith.vpsurf.de/Tolkien/Dynasty.pdf

relevance
 

The reason for being specifically interested in this, is the fact that, next to the possibly somewhat dubious half-elven descent of the princes of Dol Amroth, I cannot pinpoint any half-elven humans apart from Aragorn (and possibly the mouth of Sauron) going through all genealogies I traced..

I'd be tempted to put down the scarcity of royal descendants in Gondor to the general mental state of the Stewards, as described by Faramir to Frodo.

TTT The Window on the West

The Númenoreans in general always seem to have had more of an affinity for the past than the future, going back to the son of Elros, Vardamir Nólimon, who was so enamored of ancient history he declined to accept his place as the king.
With a precedent like that, his descendants were set for their own preoccupations that clouded their judgement on the future of their race.

Regarding what you say of the Mouth of Sauron, I know of no evidence that he would have had elven blood. As you note, even the prospect of those of Dol Amroth having it is debatable, as it was a very singular trait.

It would appear that they were more closely related to the Line of Anárion and perhaps at some point married into the Southern line in the 3rd Age. There is a section in the Heirs of Elendil that states:

"He [Eärnur] left no children. No male descendants of clear title (or nearly pure blood) of Elendil could be discovered... These may be added, for though not in direct line, the Hurinionath, the family to which Pelendur and Mardil belonged, were of Númenórean blood hardly less pure than that of the kings, and undoubtedly had some share in the actual blood of Elendil and Anárion."

Faramir discusses with the Hobbits his line; "We of my house are not of the line of Elendil, though the blood of Númenór is in us. For we reckon our line to Mardil, the good steward, who ruled in the king's stead when he went away to war. And that was King Eärnur, last of the line of Anárion, and childless, and he never came back." [TTT, ch. 5, p.328]

As we can see his house was undoubtedly pretty pure, but purity does not remain exclusive to the house of the Kings. Pure Númenóreans can be outside the house of the Kings. However, it seems not only were they a pure house of Dúnedain, they were at some point in time attached to the line of Anárion. Faramir does contradict the other text it would seem in claiming to not be of Elendil's line, but perhaps this is meant only in the sense of not in any line of succession, rather than in descent.

Since Mardil was the first of the Ruling Stewards this is why Faramir cites him as the first of his line. It is known his family line extends further back even to Pelendur, Steward of Ondoher who, "advised Gondor to reject Arvedui's claim to the crown." Further back there is Húrin who was Steward of King Minardil and from his descendants, from before the Stewardship became hereditary, were all Stewards chosen by the Kings.

Unless no King of Gondor ever had more than a single son, or any daughters- which seems very unlikely, low birthrate or not- I think we can assume they (and, therefore, Elendil) had descendants outside the direct line. That's how it works in the real world, anyway.

I believe Tolkien understood this- c.f. the passage about how "no male descendants of clear title (or nearly pure blood) of Elendil could be found". Note the qualifications: he's not saying they couldn't find any at all, just none with a good enough claim.

The problem is that branches of the family would then marry back into the main line. Things like the Civil War would have decimated the line of Elendil. Just look at the effect the War of the Roses had on House Plantagenet (though of course half of England is still descendant from them, but through illegitimate lines). The Line of the Black Prince and Henry IV were wiped out.

As you said there were other descendants of Elendil, but they were likely in conflict over the throne. In such a situation it would be best to pick somebody with no claim.

That being said I am sure the later Stewards of Gondor would be descendants of Elendil. I find it extremely unlikely the Princes of Dol Amroth had not intermarried with the royal family.

It's entirely possible that the House of Hurin was descended from one or more royal princesses, but one gets the decided impression that in the Realms in Exile (unlike Numenor) the royal succession was Salic.

OTOH, there are the implications of "pure enough blood," as if there was some notion that descendents of Elendil and of "lesser" Men were somehow tainted and ineligible, a rather distasteful position, IMO, and the sort of thing which has (wrongly) associated JRRT in some minds with white supremacists and neo-Nazis.

Well in times of war it is understandable want a military leader to be your king. A man even with the elves was more likely to be a fighter. Pelandur does claim that Gondor and even Arnor have Salic succession. I am not sure if this was true, but by saying that he would have removed any claim his House had to the throne.

The thing is we are told after the Civil War many of the Great Houses are wiped out completely. Even after the House of Hurin have ruled Gondor for around a thousand years, they are not even the second greatest House (after the Princes of Dol Amroth). In fact from Aragorn's words I get the impression there were a few Houses still in higher esteem. This leads me to believe that until later years they were not descendants of Elendil.
I think it's certain that some of the Gondor nobility believed in blood supremacy. The whole reason the Civil War happens, is because they did not want a King with mixed ancestry. I am sure certain parties would be determined to stop anyone of 'lesser blood' inherit the throne.

This is not Tolkien's view though. His only distinction for High Men and Low Men is their relationship with the elves.