Iron Hills

The Iron Hills were rich in minerals, most notably iron – whence came the name of the Hills. The Hills were originally a part of the massive Iron Mountains where Morgoth dwelt; other remains of this vanished range were the Mountains of Angmar and Ered Mithrin. The Iron Hills were also the source of the River Redwater, the reddish colour of which came from iron particles in its water. The river joins onto the River Running.

Folk of the Iron Hills
The Dwarves who first settled in the Iron Hills during the First Age were of the clan of the Longbeards, most commonly known as Durin's Folk, and consequently were of the most noble kind of Dwarves. The Hills were mined uninterruptedly for thousands of years by them, because of the hills' rich amount of iron. The Old Dwarf Road that crossed Mirkwoodwas, in fact, built by the Longbeards to connect their mansions in the Misty Mountains (namely, Khazad-dûm and Gundabad) with the Iron Hills.

Around the year 2500 of the Third Age, Grór son of Dáin I founded the Iron Hills as an independent kingdom after the Dwarves were exiled from the Grey Mountains to the west because of attacks by Cold-drakes seeking the vast wealth of the mountains, which had resulted in the death of the king Dáin I.

The exiles who settled in the Iron Hills were of course in friendly relations with the Dwarves of the Lonely Mountain (Erebor), who were of similar like and mind, being kin to Grór and Thrór.