Raseri Kanton in the Five Kings Mountains was the sister city of Jernashall. Khadon the Mighty founded the empire of Tar Khadurrm in 3279 AR and the city of Jernashall in 3312 AR. Jernashall became the preeminent city of the new empire, although Highhelm remained its capital. Jernashall became so important that the nations of Cheliax and Isger petitioned it to help them build a surface city close to it. With the help of the dwarves, the city of Raseri Kanton was founded in 3451 AR, and became a vital trade center in the region.
For 500 years, Tar Khadurrm and its cities flourished, until the Rending of Droskar's Crag in 3980 AR. The seismic and volcanic event destroyed Jernashall and its sister city of Raseri Kanton. In Jernashall, a river of lava killed every citizen within minutes. The fate of Raseri Kanton was just as horrifying: the whole city fell into the earth.