Chaul'mur'ssin

Chaul'mur'ssin was a drow city in the Plane of Shadow.

History
It was founded by the former inhabitants of Chaulssin, a city in the Underdark of Toril. The citizens of Chaulssin, called Chaulssinyr, followed the faith of Vhaeraun and refused to accept the faith of Lolth, for which the goddess decided to kill them, via the armies of Menzoberranzan, in the. Vhaeraun gave Chaulssin's leaders a warning about the impeding danger in the form of a shared dream and helped them to safely escape into the Plane of Shadow.

The Chaulssinyr, already masters of planar magic, rapidly created several portals that allowed them safe travel to their destination and to bring monsters into their city to cause great harm to their enemies from Menzoberranzan.

Once in the Plane of Shadow, the Chaulssinyr had problems with other monsters but not with the threat of an organised army, which allowed them to build the city of Chaul'mur'ssin, where their population thrived. Their success bought them the enmity of denizens of the Plane of Shadow, primarily of Clan Malaug but also of the shadovar. However, they still wanted to eventually go back to Toril. The church of Vhaeraun expanded its influence over the years and had to abruptly take control of the city in the. They found that the city's leadership was honeycombed with malaugrym, who were all killed in a single day, though at heavy casualties and the fall of the whole city's leadership. The church filled the void and, to counter future incidents like that, they founded House Jaezred, an assassins' group and the forebears of the Jaezred Chaulssin, with the duty to find and kill shapeshifter spies.

In the following years, the city fought with and learned from the malaugrym. The assassins of House Jaezred managed to get the game changer, the magic to split a zekyl's shadow dragon and drow heritages and turn the individual into a drow-dragon. The assassins gained prestige and power but to prevent internal strife in the city, they decided to go back to Toril and start to actively destroy Lolth's matriarchy as the Jaezred Chaulssin in the city of Chaulssin.

Inhabitants
The denizens of Chaul'mur'ssin were generally drow, but differed from those found on Toril. They had a number of draconic features for being the descendants of Clan Jaezred, a shadow dragon clan that enslaved their ancestors and whom they had overthrown. They had zekylen and zar'ithra'rin among their number. Even most of their drow population acquired the characteristics of shadow creatures after long exposure to the Plane of Shadow.

Other inhabitants of Chaul'mur'ssin were the Dark Bears. The Dark Bears were descendants of the quaggoths from their fallen realm of Ursadunthar. They were there as mercenaries and took on characteristics of creatures of the Plane of Shadow.