: : : : We know this was the law among the Noldor: when Turgon died
: : : : the High Kingship passed to his fairly distant nephew Rodnor
: : : : Gil-galad (son of Arothir Orodreth) rather than to his
: : : : grandson Earendil. The latter was not of male descent.

: : : Earendil was seven years old. Also I can say that the High
: : : Kingship passed to Gil-galad because he was the eldest male of
: : : the House of Fingolfin (this was, as I recall, one of the
: : : reasons Maedhros gave up the Kingship to Fingolfin and in the
: : : process, for other reasons as well, disinherited his own House
: : : from the title.

: : Gil-galad was from the House of Finarfin, not the House of Fingolfin.

What is not altogether clear is the possibility of the High Kingship being a peculiar institution in regards to inheritance. What if Turgon had died but Gondolin had not fallen. I can see a possibility that Gil-galad might have become High King of the Noldor, whilst Earendil became King of Gondolin. Gondolin having been the personal perquisite of Turgon, and therefore his to leave to his nearest kin of whatever descent, whilst the High Kingship was a pan-Noldorin institution which had to go through a patrilinear descent.

There may have been some distinction in Eldarin law between inheritance of real estate (ie a particular physical area with a kingship attached) and inheritance of tribal or folk kingship. As in the case above Dior may have been the legal inheritor of Doriath and its kingship, but not the legal heir of Thingol in his role as King of the Sindar.

A neat little twist to the argument I think ;)