§ Of Fëanor and the Unchaining of Melkor The Silmarillion

Now the Three Kindreds of the Eldar were gathered at last in Valinor, and Melkor was chained. This was the Noontide of the Blessed Realm, the fullness of its glory and its bliss, long in tale of years, but in memory too brief. In those days the Eldar became full-grown in stature of body and of mind, and the Noldor advanced ever in skill and knowledge; and the long years were filled with their joyful labours, in which many new things fair and wonderful were devised. Then it was that the Noldor first bethought them of letters, and Rúmil of Tirion was the name of the loremaster who first achieved fitting signs for the recording of speech and song, some for graving upon metal or in stone, others for drawing with brush or with pen.