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 the 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 Fëanor 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 Círdan 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 Fëanor 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.