Melkor begins to breed Orcs from enslaved Elves
Event Type: Cultural/Social
Age: Time of the Trees
Years: 1050 ~ 1085
Morgoth is thought to enslave Elves and torture them into the first Orcs:
[By] after-knowledge the wise declare that Melkor, ever watchful, was first aware of the awakening of the Quendi, and sent shadows and evil spirits to spy upon them and waylay them. So it came to pass, some years ere the coming of Oromë, that if any of the Elves strayed far abroad, alone or few together, they would often vanish, and never return; and the Quendi said that the Hunter had caught them, and they were afraid. And indeed the most ancient songs of the Elves, of which echoes are remembered still in the West, tell of the shadow-shapes that walked in the hills above Cuiviénen, or would pass suddenly over the stars; and of the dark Rider upon his wild horse that pursued those that wandered to take them and devour them. Now Melkor greatly hated and feared the riding of Oromë, and either he sent indeed his dark servants as riders, or he set lying whispers abroad, for the purpose that the Quendi should shun Oromë, if ever they should meet.
Thus it was that when Nahar neighed and Oromë indeed came among them, some of the Quendi hid themselves, and some fled and were lost....
But of those unhappy ones who were ensnared by Melkor little is known of a certainty. For who of the living has descended into the pits of Utumno, or has explored the darkness of the counsels of Melkor? Yet this is held true by the wise of Eressëa, that all those of the Quendi who came into the hands of Melkor, ere Utumno was broken, were put there in prison, and by slow arts of cruelty were corrupted and enslaved; and thus did Melkor breed the hideous race of the Orcs in envy and mockery of the Elves, of whom they were afterwards the bitterest foes. For the Orcs had life and multiplied after the manner of the Children of Ilúvatar; and naught that had life of its own, nor the semblance of life, could ever Melkor make since his rebellion in the Ainulindalë before the Beginning: so say the wise. And deep in their dark hearts the Orcs loathed the Master whom they served in fear, the maker only of their misery. This it may be was the vilest deed of Melkor, and the most hateful to Ilúvatar.
The Silmarillion, Quenta Silmarillion, Ch 3, Of The Coming of the Elves and the Captivity of Melkor
Elena Tiriel 25Dec11