Luminarian

Luminarian was a renowned night elven "magesmith" who lived before the time of the War of the Ancients. Using his legendary arcane forge, he crafted the runeblade Felo'melorn according to the description given by Dath'Remar Sunstrider.

There are some who speculate that it was a descendant of Luminarian who reforged Felo'melorn after it was shattered by Arthas Menethil during the Third War, but this assertion has never been verified.

Speculation
He may have been part of the Highborne.

After Dath'Remar became king of the high elves, the suit of armor Lu'minellia was crafted and worn by the ancient high elven kings. Its name has a similarity to Luminarian's.