Orcs... were elves?

[Inziladun]

Originally Posted by Galin

One thing I do wonder about in the Elder Days (or Second Age) is height however: orcs in general don't seem to be that tall, even the huge uruk in Moria was almost man-high, with the half-orcs being generally man-high*

Ok but by some accounts the Eldar were 6 and a half feet tall, with some kings or leaders even taller -- and by other accounts even taller, Tolkien imagining them normally 7 feet tall (especially the Noldor), equal in general to the towering Numenoreans.

The first Orcs were thought by the Eldar to have been "ruined" Avari, weren't they? They, as a rule, weren't as tall as the Noldor, I don't think. Still, though, one would think elf-blood would make Orcs fairly tall. Perhaps Morgoth began with Elves, then somewhere along the way added Dwarves to the mix. Did the Orcs of the Third Age have blood of all three races, Elves, Men, and Dwarves?