§ Of the Return of the Noldor The Silmarillion

Now in Mithrim there dwelt Grey-elves, folk of Beleriand that had wandered north over the mountains, and the Noldor met them with gladness, as kinsfolk long sundered; but speech at first was not easy between them, for in their long severance the tongues of the Calaquendi in Valinor and of the Moriquendi in Beleriand had drawn far apart. From the Elves of Mithrim the Noldor learned of the power of Elu Thingol, King in Doriath, and the girdle of enchantment that fenced his realm; and tidings of these great deeds in the north came south to Menegroth, and to the havens of Brithombar and Eglarest. Then all the Elves of Beleriand were filled with wonder and with hope at the coming of their mighty kindred, who thus returned unlocked-for from the West in the very hour of their need, believing indeed at first that they came as emissaries of the Valar to deliver them.