"Ayleids, also known as the Ancient Ones, Wild Elves, or Heartland High Elves, were the first race to establish an empire in Tamriel. They were the original founders of the Imperial City, although it was a fortress called White Gold Tower in those days. They spoke a language now referred to as "Ayleidoon", a derivative of Aldmeris which was once the language of the human Cyrodils as well. Much like the lost Dwemer (whose ruins can be found in Hammerfell and Morrowind), many Ayleid ruins can be found in Cyrodiil."
http://www.uesp.net/wiki/Oblivion:Ayleids
Like Dwarven armor was found in the many Dwemer ruins that dotted across Tamriel, Elven armor was found in the many Aylied ruins that are dotted across Tamriel.
To confirm this we have various Aylied unique armor pieces which are obviously identifyable to Elven armor.
http://www.uesp.net/wiki/Oblivion:Ayleid_Crown_of_Lindai
http://www.uesp.net/wiki/Oblivion:Ayleid_Crown_of_Nenalata
Am I correct?
It isn't Orsimer / Orc (corrupt Elves) as Orcish armor is much different.
http://www.uesp.net/wiki/File:OB-item-Orcish_Armor.jpg
It isn't Altmer (High Elves) armor as in Morrowind it states that the orcish armor of Morrowind was copied from Altmer armor. Altmer racially aren't suited for light armor so it would not make sense for it to be theirs.
http://www.uesp.net/wiki/Morrowind:Orcish_Armor#Orcish_Armor
http://www.uesp.net/wiki/File:MW_Armor_OrcishM.jpg
We know it is Dunmer (Dark Elves) as we see Dunmer armor in Morrowind.
http://www.uesp.net/wiki/Morrowind:Bonemold
http://www.uesp.net/wiki/Morrowind:Chitin
Bosmer are greatly suited for light armor yet is it likely that their lifestyle and civilization would make such as splendid design?