Belegost lay the central part of the Ered Luin, and was home to the Dwarven House known as the Broadbeams. Its name in Khuzdul was Gabilgathol probably meaning "great fortess". Belegost in Sindarin translates as "Great Fortress" as well. Its lord until Nirnaeth Arnoediad was Azaghâl.
The Dwarves of Belegost were friends to the Sindar and later also the Ñoldor of Beleriand. They did not join the Dwarves of Nogrod in the Sack of Doriath, and actually attempted to dissuade their kinsman from it.
Unlike Nogrod to the South, Belegost may have partly survived after the War of Wrath, although it was recorded as having been 'ruined' at that time: many Dwarves of Belegost joined Durin's folk in Khazad-dûm 60 years after the war, but there were always Dwarves on the Eastern side of the mountains.