The Silmarillion

Now the lords of the Noldor held council in Mithrim, and thither came Angrod out of Doriath, bearing the message of King Thingol. Cold seemed its welcome to the Noldor, and the sons of Feanor were angered at the words; but Maedhros laughed, saying: 'A king is he that can hold his own, or eke his title is vain. Thingol does but grant us lands where his power does not run. Indeed Doriath alone would be his realm this day, but for the coming of the Noldor. Therefore in Doriath let him reign, and be glad that he has the sons of Finwe for his neighbours, not the Orcs of Morgoth that we found. Elsewhere it shall go as seems good to us."

But Caranthir, who loved not the sons of Finarfin, and was the harshest of the brothers and the most quick to anger, cried aloud: 'Yea more! Let not the sons of Finarfin run hither and thither with their tales to this Dark Elf in his caves! Who made them our spokesmen to deal with him? And though they be come indeed to Beleriand, let them not so swiftly forget that their father is a lord of the Noldor, though their mother be of other kin.'

Then Angrod was wrathful and went forth from the council. Maedhros indeed rebuked Caranthir; but the greater part of the Noldor, of both followings, hearing his words were troubled in heart, fearing the fell spirit of the sons of Feanor that it seemed would ever be like to burst forth in rash word or violence. But Maedhros restrained his brothers, and they departed from the council, and soon afterwards they left Mithrim and went eastward beyond Aros to the wide lands about the Hill of Himring. That region was named thereafter the March of Maedhros; for northwards there was little defence of hill or river against assault from Angband. There Maedhros and his brothers kept watch, gathering all such people as would come to them, and they had few dealings with their kinsfolk westward, save at need. It is said indeed that Maedhros himself devised this plan, to lessen the chances of strife, and because he was very willing that the chief peril of assault should fall upon himself; and he remained for his part in friendship with the houses of Fingolfin and Finarfin, and would come among them at times for common counsel. Yet he also was bound by the oath, though it slept now for a time.

Now the people of Caranthir dwelt furthest east beyond the upper waters of Gelion, about Lake Helevorn under Mount Rerir and to the southward; and they climbed the heights of Ered Luin and looked eastward in wonder, for wild and wide it seemed to them were the lands of Middle-earth. And thus it was that Caranthir's people came upon the Dwarves, who after the onslaught of Morgoth and the coming of the Noldor had ceased their traffic into Beleriand. But though either people loved skill and were eager to learn, no great love was there between them; for the Dwarves were secret and quick to resentment, and Caranthir was haughty and scarce concealed his scorn for the unloveliness of the Naugrim, and his people followed their lord. Nevertheless since both peoples feared and hated Morgoth they made alliance, and had of it great profit; for the Naugrim learned many secrets of craft in those days, so that the smiths and masons of Nogrod and Belegost became renowned among their kin, and when the Dwarves began again to journey into Beleriand all the traffic of the dwarf-mines passed first through the hands of Caranthir, and thus great riches came to him.

When twenty years of the Sun had passed, Fingolfin King of the Noldor made a great feast; and it was held in the spring near to the pools of Ivrin, whence the swift river Narog rose, for there the lands were green and fair at the feet of the Mountains of Shadow that shielded them from the north. The joy of that feast was long remembered in later days of sorrow; and it was called Mereth Aderthad, the Feast of Reuniting. Thither came many of the chieftains and people of Fingolfin and Finrod; and of the sons of Feanor Maedhros and Maglor, with warriors of the eastern March; and there came also great numbers of the Grey-elves, wanderers of the woods of Beleriand and folk of the Havens, with Cirdan their lord. There came even Green-elves from Ossiriand, the Land of Seven Rivers, far off under the walls of the Blue Mountains; but out of Doriath there came but two messengers, Mablung and Daeron, bearing greetings from the King.

At Mereth Aderthad many counsels were taken in good will, and oaths were sworn of league and friendship; and it is told that at this feast the tongue of the Grey-elves was most spoken even by the Noldor, for they learned swiftly the speech of Beleriand, whereas the Sindar were slow to master the tongue of Valinor. The hearts of the Noldor were high and full of hope, and to many among them it seemed that the words of Feanor had been Justified, bidding them seek freedom and fair kingdoms in Middle-earth; and indeed there followed after long years of peace, while their swords fenced Beleriand from the ruin of Morgoth, and his power was shut behind his gates. In those days there was joy beneath the new Sun and Moon, and all the land was glad; but still the Shadow brooded in the north.

And when again thirty years had passed, Turgon son of Fingolfin left Nevrast where he dwelt and sought out Finrod his friend upon the island of Tol Sirion, and they journeyed southward along the river, being weary for a while of the northern mountains; and as they journeyed night came upon them beyond the Meres of Twilight beside the waters of Sirion, and they slept upon his banks beneath the summer stars. But Ulmo coming up the river laid a deep sleep upon them and heavy dreams; and the trouble of the dreams remained after they awoke, but neither said aught to the other, for their memory was not clear, and each believed that Ulmo had sent a message to him alone. But unquiet was upon them ever after, and doubt of what should befall, and they wandered often alone in untrodden lands, seeking far and wide for places of hidden strength; for it seemed to each that he was bidden to prepare for a day of evil, and to establish a retreat, lest Morgoth should burst from Angband and overthrow the armies of the North.

Now on a time Finrod and Galadriel his sister were the guests of Thingol their kinsman in Doriath. Then Finrod was filled with wonder at the strength and majesty of Menegroth, its treasuries and armouries and its many-pillared halls of stone; and it came into his heart that he would build wide halls behind ever-guarded gates in some deep and secret place beneath the hills. Therefore he opened his heart to Thingol, telling him of his dreams; and Thingol spoke to him of the deep gorge of the River Narog, and the caves under the High Faroth in its steep western shore, and when he departed he gave him guides to lead him to that place of which few yet knew. Thus Finrod came to the Caverns of Narog, and began to establish there deep halls and armouries after the fashion of the mansions of Menegroth; and that stronghold was called Nargothrond. In that labour Finrod was aided by the Dwarves of the Blue Mountains; and they were rewarded well, for Finrod had brought more treasures out of Tirion than any other of the princes of the Noldor.