The Silmarillion

For nigh on two years after the Dagor Bragollach the Noldor still defended the western pass about the sources of Sirion, for the power of Ulmo was in that water, and Minas Tirith withstood the Orcs. But at length, after the fall of Fingolfin, Sauron, greatest and most terrible of the servants of Morgoth, who in the Sindarin tongue was named Gorthaur, came against Orodreth, the warden of the tower upon Tol Sirion. Sauron was become now a sorcerer of dreadful power, master of shadows and of phantoms, foul in wisdom, cruel in strength, misshaping what he touched, twisting what he ruled, lord of werewolves; his dominion was torment. He took Minas Tirith by assault, for a dark cloud of fear fell upon those that defended it; and Orodreth was driven out, and fled to Nargothrond. Then Sauron made it into a watchtower for Morgoth, a stronghold of evil, and a menace; and the fair isle of Tol Sirion became accursed, and it was called Tol-in-Gaurhoth, the Isle of Werewolves. No living creature could pass through that vale that Sauron did not espy from the tower where he sat. And Morgoth held now the western pass, and his terror filled the fields and woods of Beleriand. Beyond Hithlum he pursued his foes relentlessly, and he searched out their hiding-places and took their strongholds one by one. The Orcs growing ever bolder wandered at will far and wide, coming down Sirion in the west and Colon in the east, and they encompassed Doriath; and they harried the lands so that beast and bird fled before them, and silence and desolation spread steadily from the North. Many of the Noldor and the Sindar they took captive and led to Angband, and made them thralls, forcing them to use their skill and their knowledge in the service of Morgoth. And Morgoth sent out his spies, and they were clad in false forms and deceit was in their speech; they made lying promises of reward, and with cunning words sought to arouse fear and jealousy among the peoples, accusing their kings and chieftains of greed, and of treachery one to another. And because of the curse of the Kinslaying at Alqualondë these lies were often believed; and indeed as the time darkened they had a measure of truth, for the hearts and minds of the Elves of Beleriand became clouded with despair and fear. But ever the Noldor feared most the treachery of those of their own kin, who had been thralls in Angband; for Morgoth used some of these for his evil purposes, and feigning to give them liberty sent them abroad, but their wills were chained to his, and they strayed only to come back to him again. Therefore if any of his captives escaped in truth, and returned to their own people, they had little welcome, and wandered alone outlawed and desperate.

To Men Morgoth feigned pity, if any would hearken to his messages, saying that their woes came only of their servitude to the rebel Noldor, but at the hands of the rightful Lord of Middle-earth they would get honour and a just reward of valour, if they would leave rebellion. But few men of the Three Houses of the Edain would give ear to him, not even were they brought to the torment of Angband. Therefore Morgoth pursued them with hatred; and he sent his messengers over the mountains.

It is told that at this time the Swarthy Men came first into Beleriand. Some were already secretly under the dominion of Morgoth, and came at his call; but not all, for the rumour of Beleriand, of its lands and waters, of its wars and riches, went now far and wide, and the wandering feet of Men were ever set westward in those days. These Men were short and broad, long and strong in the arm; their skins were swart or sallow, and their hair was dark as were their eyes. Their houses were many, and some had greater liking for the Dwarves of the mountains than for the Elves. But Maedhros, knowing the weakness of the Noldor and the Edain, whereas the pits of Angband seemed to hold store inexhaustible and ever-renewed, made alliance with these new-come Men, and gave his friendship to the greatest of their chieftains, Bór and Ulfang. And Morgoth was well content; for this was as he had designed. The sons of Bór were Borlad, Borlach, and Borthand; and they followed Maedhros and Maglor, and cheated the hope of Morgoth, and were faithful. The sons of Ulfang the Black were Ulfast, and Ulwarth, and Uldor the accursed; and they followed Caranthir and swore allegiance to him, and proved faithless.