The Ered Wethrin ran along the southern and eastern edges of Hithlum and had few passes. The north-western boundary of Hithlum was formed by the Ered Lómin (Echoing Mountains) which curved to meet Helcaraxë. The land of Nevrast was separated from Hithlum by the southern part of the Ered Lómin. Nevrast was usually seen as part of Hithlum but more closely resembled the rest of Beleriand. Lammoth lay to the west. Hithlum's climate was cold and wet, however, the soil was quite rich. The Ñoldor made their first landing at the Firth of Drengist and first camped at the shores of Lake Mithrim.
Hithlum became the realm of the ruling Ñoldor living in exile in Middle-earth. Hithlum contained Mithrim and Dor-lómin. Mithrim was the seat of the High Kings of the Ñoldor while Dor-lómin later became a fief of the House of Hador.
During the later part of the First Age, Hithlum was repeatedly attacked by the forces of Morgoth. Hithlum was lost to Morgoth after the Nirnaeth Arnoediad (Battle of Unnumbered Tears). The Men of the House of Hador in Dor-lómin were either scattered, killed, or enslaved, while the Ñoldor of Mithrim who failed to flee were enslaved in Morgoth's mines. When Morgoth betrayed the Easterlings, he imprisoned them in Hithlum.
Hithlum, like the rest of Beleriand, was completely destroyed and sunk during the War of Wrath.
|Elven Realms of Middle-earth throughout the Ages|
|Years of the Trees:||Cuiviénen | Eglador | Havens of the Falas|
|First Age:||Doriath | Dorthonion | Gondolin | Havens of Sirion | Havens of the Falas | Himlad & Pass of Aglon | Hithlum | Maglor's Gap | March of Maedhros | Nargothrond | Nevrast | Ossiriand | Pass of Sirion | Thargelion|
|Second Age:||Eregion | Greenwood the Great | Lindon | Rivendell|
|Third Age:||Lindon | Lothlórien | Northern Mirkwood | Rivendell|
|Fourth Age:||Lindon | Lothlórien & East Lórien | Rivendell | Wood of Greenleaves|
- The Atlas of Middle-earth pg. 14