Originally founded in 3312 AR by the dwarven hero Khadon the Mighty, Jernashall became important enough for the nations of Cheliax and Isger to petition the dwarves to help them build the surface city of Raseri Kanton near Jernashall, for the purposes of trade and diplomacy. They agreed, and in 3451 AR, the sister-city was completed.
Within a few decades, Jernashall was declared the new capital of Tar Khadurrm, replacing Highhelm as the most important dwarven city. In 3332 AR, the engineers of Jernashall completed the first magmafall, one of the greatest feats of engineering of its time. For 500 years the importance and prosperity of Jernashall grew, and it became the center of dwarven life in the Five Kings Mountains.
By the 3900s, whispers began to circulate that the volcanic Droskar's Crag (then known as Torag's Crag) may be set to erupt. The dwarves paid no heed to these warnings however, convinced that the engineering skills of their forefathers would protect them from any natural threat.
The end finally came in 3980 AR. Jernashall was battered and shaken by the inevitable eruption, but remained standing. Under the mistaken belief that their stronghold had withstood the great tremors unscathed, the dwarves shrugged off the event and continued unabated. Unbeknownst to them, however, the initial quake had weakened the foundations of the city. The next day another eruption occurred and the devastation was immense. The great magmafall in the center of the city spewed forth a river of lava, spilling throughout the city slaying its residents. Raseri Kanton was not spared the disaster, and fell into the earth. Only a handful of buildings in the uppermost reaches remained intact, and nearly every resident in either settlement perished. The event became know as the Rending, and marked the decline of the empire of Tar Khadurrm.
- David Eitelbach, Russ Taylor, JD Wiker, Keri Wiker, and Hank Woon. (2009). Dwarves of Golarion, p. 5. Paizo Publishing, LLC. ISBN 978-1-60125-204-3
- David Eitelbach, Russ Taylor, JD Wiker, Keri Wiker, and Hank Woon. (2009). Dwarves of Golarion, p. 9. Paizo Publishing, LLC. ISBN 978-1-60125-204-3
- James Jacobs et al. (2011). The Inner Sea World Guide, p. 67. Paizo Publishing, LLC. ISBN 978-1-60125-269-2