Istar

The Istar are elves that choose to value knowledge over everything else. One of the first factions to form amongst the elves after the Ellarian war, they originally sought a way to preserve the knowledge and history of the elven people since so many of their cities had been raided and captured by the humans. It was the Istar that first learned how to change their biology in an attempt to grant themselves higher intelligence and mental capacity. As a result they grew taller than your average elf and their skin turned grey. As time progressed the high council of the elves gained more and more istar untill they completely overtook it and they locked off the upper levels of Ambar Nimloth, The World Tree, by magical barriers only Istar can cross. Because of the gradual change over centuries and the groups peaceful but structured fundamentals they were met with little to no opposition from their fellow elves. Since then the Istar have governed the elven people from above, controlling the larger decisions of elven government and arcane arts.