[Formendacil]

Finwe, High King of the Noldor, was succeeded by his son Feanor, who's son Maedhros gave up the claim, which was subsequently passed on to Fingolfin, who was succeeded by Fingon, who was succeeded by Turgon. Turgon was succeeded by Gil-Galad.

Gil-Galad was the last High King of the Noldor in Middle-Earth. He was not, however, the last King of the Noldor, since the Noldor of Valinor were ruled from the departure of Feanor onwards by Finarfin son of Finwe.

A close reading of the Lord of the Rings, the Silmarillion, and Unfinished Tales, not to mention the entire HoME, is in complete agreement here: Gil-Galad was High King of the Noldor following Turgon, and he was the last to bear that title.

The curiosity is where on the family tree Gil-galad lies. Christopher Tolkien, in the published Silm, placed him as the son of Fingon, Turgon's elder brother, and therefore the proper heir before him. However, Christopher Tolkien acknowedged later that this was an ephemeral idea, and shouldn't have been credited. Tolkien's ultimate decision, or LAST decision rather, was to make him the son of Orodreth, son of Angrod, son of Finarfin, son of Finwe, and so confusingly being made High King over the elder lines of descent represented by Idril and her descendents: Earendil and Elrond.

One might make the claim, of course, that the mortal blood of Earendil and Elrond negated their claims to the Noldorin throne. However, I seem to recall, somewhere in the back of my head, a statement in either Unfinished Tales or Of the Rings of Power and the Third Age that Elrond, after the death of Gil-galad, was the rightful High King of the Noldor, but refused to take the title due to a general lack of Noldor left to call a Kingdom.

Personally, I've always liked to toy with the idea that Gil-Galad was the son of Arakano (Argon), the third son of Fingolfin, only mentioned in passing in the Shibboleth of Feanor- but this is a completely uncanonical, unsubstantiated, and personal preference here.

The basic point is that Gil-galad was High King of the Noldor in Middle-Earth following the death of Turgon. He seems to have been the last male descendent of male lineage from Finwe (other than Celebrimbor who predeceased him anyway), so perhaps that is why he was also the last High King of the Noldor.