Taur-nu-Fuin was a name for the northern parts of Dorthonion, and sometimes for the forest as a whole after it was corrupted by Morgoth after the Dagor Bragollach. The kingdoms of Dorthonion were destroyed at that point, including Ladros and the realm Angrod and Aegnor. Barahir remained as an outlaw in Taur-nu-Fuin, and after his death Beren his son dwelt in this forest for several years, before crossing the Ered Gorgoroth and forsaking Dorthonion to its captors. Then it was truly wholly "under nightshade".
