: That's how a normal morarchy works, yes. But I for some reason don't concider the title High King over the Noldor to be the same thing as a normal monarchy. The high king does not have the same power as a European king in the middle ages. Fingolfin was the high king for long, but I don't think he could command any of Finrods people. The institution was so loose so an heridetary kingship would not seem logically to me. (don't ask me to explain why)

Why? Look at the modern British crown. No power but succession is a very important issue.

: To appoint the oldest male person of Finwes house as high king would seem more appropriate.

Regardless of what power the high king had (and I agree it appeared to be nominal), there had to be some sort of system that determined how the crown passed.

In App B (and elsewhere), Tolkien uses the work "heir" to refer to the passing of the Noldorin high crown. Gil-galad was specifically referred to as the last heir; yet we know Elrond was descended from Finwe. So there must have been some reason why he wasn't an heir to the Noldorin throne.

The term was also used to refer to the crown of Gondolon and specifically, Turgonnot having an heir because his only child was a female. Nor was Earendil considered Turgon's heir AFAIK.

Thus, at minimum, under Noldorin law and/or custom females and males of female-lines appear to be excluded from the line of succession.

I think it's also relevant that the exilic crown, once established, did pass to the eldest male of the senior male-line. I'd be curious if any of the Annals or Tales of Years states whether Finarfin's eldest son was older than Fingolfin's second son Turgon. Since after Fingon's death the crown passed to Turgon, this could be a relevant consideration.

I think its also relevant that the original Numenorean succession law - which we are told about explicitly by Tolkien in Aldarion and Erendis - was a strict promigeniture system. It's quite likely that the Numeoreans would have adopted Noldorin custom in that regard.

Russ