Orcs: History

Many Orcs (along with fallen Maiar and other evil servants of Melkor) survived in the deep caves, pits, chambers, and tunnels of Melkor's great underground fortresses of Utumno and Angband. They multiplied and later spread through northern Middle-earth. They were first seen by the Dwarves who reported them to Thingol, King of Doriath, causing the latter to seek weapons of war for the first time. For over a millennium, the Orcs were only a minor problem, but when Melkor (Morgoth) returned with the Silmarils he took full charge of them and soon unleashed them on Beleriand. The newly organized Orcs killed Denethor, the King of the lightly armed Laiquendi, but were eventually defeated by Thingol and his allies. They besieged the Havens of the Falas under Círdan, and the siege wasn't broken until the arrival of the Ñoldor. The heavy losses that the Sindar suffered at the hands of the Orcs frightened them to the point that Melian, Queen of Doriath raised a great enchantment to protect their kingdom. The Laiquendi, who suffered the most in the battle, hid themselves in Ossiriand under the cloak of secrecy, or took refuge in Doriath.