§ Of the Beginning of Days The Silmarillion

But as the ages drew on to the hour appointed by Ilúvatar for the coming of the Firstborn, Middle-earth lay in a twilight beneath the stars that Varda had wrought in the ages forgotten of her labours in Eä. And in the darkness Melkor dwelt, and still often walked abroad, in many shapes of power and fear, and he wielded cold and fire, from the tops of the mountains to the deep furnaces that are beneath them; and whatsoever was cruel or violent or deadly in those days is laid to his charge.