§ Of Beleriand and Its Realms The Silmarillion

This is the fashion of the lands into which the Noldor came, in the north of the western regions of Middle-earth, in the ancient days; and here also is told of the manner in which the chieftains of the Eldar held their lands and the leaguer upon Morgoth after the Dagor Aglareb, the third battle in the Wars of Beleriand.