Orcs > Orc Origins > "Orcs"
In the Silmarillion it is said that in
the Dark Days Morgoth
enslaved all Elves whom dared roam near his lands. Those who
were taken were tortured for a lifetime of tears. Then, he bred
them into hideous monsters (in derision of the Elves, who became their
bitterest foes). Elves were
harassed by them for all their ages in Middle-earth. Orcs multiplied
the manner of the Quendi and they had life, but no life of their
own. Veiled in these mindless monsters' hearts they resented Morgoth,
maker of their misery, but it it was he whom they served--
in great fear.
Reference: The Silmarillion