
Three centuries pass, during which the first Men appear in Beleriand. Together with the Sindar of Beleriand, they proceed to lay siege to Angband, and establish new strongholds and realms in Middle-earth, including Hithlum ruled by Fingon, Nargothrond by Finrod Felagund and Gondolin by Turgon. In addition, after some time the Noldorin Elves forsake Valinor and pursue Morgoth to Middle-earth in order to take vengeance upon him. However, the Elves manage to stay his assault, and most of their realms remain unconquered one of the most powerful of these is Doriath, ruled by Thingol.

From his fortress of Angband he endeavours to gain control of the whole of Middle-earth, unleashing a war with the Elves that dwell in the land of Beleriand to the south. It begins five hundred years before the action of the book, when Morgoth, a Vala and the prime evil power, escapes from the Blessed Realm of Valinor to the north-west of Middle-earth.

The history and descent of the main characters are given as the leading paragraphs of the book, and the back story is elaborated upon in The Silmarillion.
