§ Of the Return of the Noldor The Silmarillion

Under the cold stars before the rising of the Moon the host of Fëanor went up the long Firth of Drengist that pierced the Echoing Hills of Ered Lómin, and passed thus from the shores into the great land of Hithlum; and they came at length to the long lake of Mithrim, and upon its northern shore made their encampment in the region that bore the same name. But the host of Morgoth, aroused by the tumult of Lam-moth and the light of the burning at Losgar, came through the passes of Ered Wethrin, the Mountains of Shadow, and assailed Fëanor on a sudden, before his camp was full-wrought or put in defence; and there on the grey fields of Mithrim was fought the Second Battle in the Wars of Beleriand. Dagor-nuin-Giliath it is named, the Battle-under-Stars, for the Moon had not yet risen; and it is renowned in song. The Noldor, outnumbered and taken at unawares, were yet swiftly victorious; for the light of Aman was not yet dimmed in their eyes, and they were strong and swift, and deadly in anger, and their swords were long and terrible. The Orcs fled before them, and they were driven forth from Mithrim with great slaughter, and hunted over the Mountains of Shadow into the great plain of Ard-galen, that lay northward of Dorthonion. There the armies of Morgoth that had passed south into the Vale of Sirion and beleaguered Círdan in the Havens of the Falas came up to their aid, and were caught in their ruin. For Celegorm, Fëanor's son, having news of them, waylaid them with a part of the Elven-host, and coming down upon them out of the hills near Eithel Sirion drove them into the Fen of Serech. Evil indeed were the tidings that came at last to Angband, and Morgoth was dismayed. Ten days that battle lasted, and from it returned of all the hosts that he had prepared for the conquest of Beleriand no more than a handful of leaves.