Chaulssin Chaulssin is a drow city in the Underdark . To some people it is also known as the City of Wyrmshadows . Chaulssin lies beneath the northern Rauvin Mountains . It overhangs an extremely deep abyss and cold winds howl permanently through the city . It rests upon a great spar of stone . After it was conquered by shadow dragon s and ruled by their descendants the city was partially brought into the Plane of Shadow . Tendrils of shadow - stuff wind all the time through the city and deadly shadow creatures haunt the streets . Sometimes whole quarters of the city vanish into the Plane of Shadow and reappear years later . Due to its remote location and its little known history Chaulssin is largely unknown to most inhabitants of the Underdark , let alone the World Above . This fact makes it a perfect stronghold for the secret brotherhood of the Jaezred Chaulssin . In the time of the War of the Spider Queen it was only a faint shadow of its former self . Most of the city stood empty and was only patrolled intermittently by tribes of Dark bears or claimed by small bands of Shadar - kai . The zekylyn lived alone in the upper reaches of the city ' s great galleries . There they trained under the watchful eyes of the Patron Fathers . The zar ' thra ' rin claimed the lesser tunnels of Chaulssin for their own , where they hunted the interlopers from the Plane of Shadow and the surrounding Underdark . They were organized in wolf packs , dominated by the strongest male . The ilharen ' quarthen dwelled in the heart of Chaulssin . They were the female concubines of the Patron Fathers and lived in lavish apartments surrounding the great lair of Patron Grandfather Mauzzkyl Jaezred . The other Patron Grandfathers visited their concubines in Chaulssin regularly , for each of them had only a handful of females with them in their respective cities . Today the city is the headquarter of the infamous Jaezred Chaulssin , an organization of powerful assassins and worshipers of Vhaeraun . History . Chaulssin was originally a drow city until - 221 DR ( Year of Shambling Shadows ) , when a clan of shadow dragons known as the Jaezred conquered it and enslaved the inhabitants . The title " City of Wyrmshadows " became one of the city ’ s names due to this event . For centuries , the Jaezred cruelly ruled Chaulssin , driving the drow nearly to extinction . They furthermore carried out magical experiments on the elves , twisting them into creatures of shadow , and even interbred with them . Out of these couplings came a race of half - drow , half - dragon creatures known as zekylyn . The Jaezred also attempted to shift the entire city itself onto their home plane , the Plane of Shadow . However , while pretending to serve their dragon masters , the zekylyn were secretly studying powerful planar magic on their own . In 634 DR ( Year of the Darkspawn ) , they launched a successful rebellion against the Jaezred , slaying and reanimating most of them as spectral creatures . One of the few who managed to escape was Haernivureem , who would later conquer the dwarven city of Mithral Hall , where he was known as Shimmergloom . The new rulers of Chaulssin , meanwhile , set about rebuilding it with the wealth the shadow dragons had hoarded over the years , which itself had been plundered from the zekylyn ’ s original drow ancestors . Around this time as well , missionaries of Lolth started arriving from the other drow cities of Ched Nasad , Menzoberranzan , and Jhachalkhyn . The leaders of the Chaulssinyr , though , who were mostly male , rebuffed them repeatedly . Exile in the Plane of Shadow . In 734 DR ( Year of Visions ) , Vhaeraun appeared to the leaders of Chaulssin and revealed to them that Lolth had decided to punish them for their defiance . Lolth instructed the ruling council of Menzoberranzan to dispatch a massive army to conquer the city . The patriarchs of the City of Wyrmshadows chose to withdraw rather than make a suicidal stand . They opened portals to the Plane of Shadow and left the city . When the drow arrived a few days later they found only an abandoned city wrapped in the coils of the Shadow Fringe . The monsters from the Plane of Shadow pressed on them and the Menzoberranzanyr suffered heavy losses . Since there was little to show for their expedition they decided to claim victory and retreated , believing the flight of the Chaulssinyr was due to the might of the Spider Queen . The former inhabitants of Chaulssin encountered all manner of dangerous creatures on the Plane of Shadow , but at least no hostile army intending to kill them . They walked for miles through the Plane of Shadow and reached the abandoned lairs of their draconic ancestors from the Jaezred Clan which they claimed as their own . Here they began to build a new city for themselves , named Chaul ' mur ' ssin . But times were hard until the inhabitants learned to adapt to the rigors of the Plane of Shadow . Over time , though , the people themselves changed and became more attuned to their environment , losing a large measure of their Prime Material nature . They gradually became stronger , becoming a threat to other planar interlopers , like the scions of Clan Malaug , and to a lesser extent the Shadovar of Thultanthur . A new vision revealed to the priesthood of Vhaeraun in 792 DR ( Year of the Crimson Thorn ) that the leadership of the Chaulssinyr had been infiltrated by the malaugrym . Only at the cost of many lives and the collapse of the city ' s patriarchy were the shapeshifters finally unmasked and put to sword . In response the Church of Vhaeraun assumed power and founded House Jaezred , an elite brotherhood of assassins trained to ferret out and kill shapeshifters . Through this the conflict between Clan Malaug and the Chaulssinyr waxed and waned , with neither gaining permanent advantage . But the zekylyn learned from their enemies how to split their dual natures and alternate their forms between drow and dragon , in so doing becoming the first drow - dragons . House Jaezred earned the respect of all Chaulssinyr due to this , and the leaders of the house threatened to eclipse the authority of the ruling Vhaeraunite priesthood . Return of the Shadowkin . There was now internal strife between the brotherhood of House Jaezred and the clergy of Vhaeraun , with the clergy still nominally in charge . To avoid civil strife the patriarchs of House Jaezred agreed to return to Faerûn . There they would hold dear the debt of the Chaulssinyr to the Masked Lord and work to undermine the rule of Lolth . But this was also the start of an effort to distance themselves from the Masked Lord and his followers . In 1136 DR ( Year of Shadowkin Return ) House Jaezred returned to Chaulssin , where they established the House of Hidden Masters in its heart . There they started to call themselves Jaezred Chaulssin . The City of Wyrmshadows was a perfect place as a base of operations for the House leadership , but it was deemed to be too dangerous to raise the next generation of assassins . The patron fathers therefore decided to establish fosterages in the guise of minor noble houses in seven drow cities ruled by followers of the Spider Queen . This should have happened in Ched Nasad , Eryndlyn , Karsoluthiyl , Jhachalkhyn , Maerimydra . Sschindylryn and Menzoberranzan . But Menzoberranzan proved to be resistant to infiltration and so Dusklyngh was chosen instead as the seventh fosterage . Jaezred Chaulssin also established half a dozen smaller fosterages throughout the Underdark where Lolth ' s power was minor but drow could walk openly , like in Skullport or Sshamath ( the monastery Vhaidra Uoswiir attacks might have been one of these ) . Threat from the Shapeshifters . During the Harpstar Wars ( 1182 DR – 1222 DR ) the shapeshifters of Clan Malaug captured a spy of the Harpers . This spy had previously explored Chaulssin and so Clan Malaug learned of the return of their enemy to Faerûn . Only their own losses in the war prevented them from attacking the City of Wyrmshadows and they needed time until 1241 DR ( Year of the Lost Lady ) to become strong enough . In this year a raiding party of malaugrym managed to kidnap a pregnant concubine of the Patron Grandfather . The assassins of Jaezred Chaulssin tracked them down and killed the interlopers before they reached Castle Malaug , but the concubine vanished during the fight . The War of the Spider Queen . After centuries of secret activities and infiltration of the seven drow cities ruled by Lolth ' s followers the year 1372 DR ( Year of Wild Magic ) promised to be the most important one for the plans of Jaezred Chaulssin . Now they saw the opportunity to strike several Lolth - ruled cities at once . They had their hands in the plot which brought stone fire bombs to Ched Nasad and caused the destruction of the whole city . In Eryndlyn they brought the followers of Vhaeraun and Ghaunadaur together against the church of Lolth and decimated the ranks of her followers drastically . Smaller strikes in Dusklyngh , Jhachalkhyn and Karsoluthiyl weakened the hold of the ruling Matron Mothers and helped the male - dominated merchant houses to gain influence . However in Maerimydra their plots crossed with Kiaransalee ' s , and her followers won out and claimed the city for their own . In Menzoberranzan , the invasion of the duergar armies of Gracklstugh and the tanarukk of the Sceptered Legion failed . Since the end of this war the patron fathers have begun to cement their control over the ruins of Ched Nasad and their influence on the factions of Eryndlyn . They also receive tribute from the merchant houses under their control in Dusklyngh , Karsoluthiyl and Jhachalkhyn . Vhaeraun is killed by his sister Eilistraee ( Nightal 20 , 1375 DR ) , when he attempted to enter her realm and assassinate her . His portfolio was taken by her at that time . What has happened to Chaul ’ mur ’ ssin is unknown . 1379 DR His sister Eilistraee , while inhabiting the body of Qilué Veladorn , was killed by Halisstra Melarn using the Crescent Blade . Areas of Interest . Galleries of Shadow . The Galleries of Shadow encompass the lesser halls and chambers of the city linked by tunnels . They are not considered part of the House of Hidden Masters . Packs of Zar ' ihtra ' rin , companies of Dark bears and small bands of Shadar - kai consider it home . Interlopers from the Plane of Shadow are not uncommon where the Shadow Fringe is close . Howling Abyss . Chaulssin rests on a huge spar of stone at the edge of a great chasm in the earth . It is known as the Howling Abyss which extends at least three miles above the city and more than seventeen miles into the depths . Winds with the force of Hurricanes buffet the city of Chaulssin relentlessly , threatening to sweep away anyone that dares to show his face on the city ' s battlements or attempts to fly through the chasm . The Howling Abyss is home to dangerous creatures , like Belkers and voidwraiths . The spectral - shadow dragons , reanimated undead of the former rulers of Clan Jaezred roam through the city they once ruled and defend it against interlopers . House of Hidden Masters . At the heart of Chaulssin lies the House of Hidden Masters . It is the chapterhouse of the Jaezred Chaulssin and resides in what was once the city ' s largest temple to Lolth . In the center of the temple lies the opulent lair of Patron Grandfather Mauzzkyl Jaezred ( as of 1372 DR ) . The walls hang with tapestries of woven shadowstuff that depict distorted images of scenes long forgotten . The floor is piled high with tarnished coins of varying mintage and design . Glistening onyx embedded with beljurils form the arched ceiling . The lair of the old dragon is surrounded by lavish apartments of the concubines ( known as ilharen ' qarthen ) . Each of them resembles a small version of the main lair and is heavily guarded , for the Patron Fathers do not trust each other to steal a rival favored concubine . The inhabitants of each harem largely govern themselves when the masters are absent . But if worship of other gods is unearthed it will be ruthlessly stomped out . Shadow Fringe . The City of Wyrmshadows exists partially in the Plane of Shadow . Tendrils of shadowstuff constantly wind through its ruins , ebbing and flowing with the pull of some erratic , unseen moon . With this deadly creatures of the Plane of Shadow cross the planar borders and haunt the streets . From time to time whole quarters vanish into the gloom entirely and reappear years later . Groups of Power in Chaulssin . Chaulssin is dominated by the Jaezred Chaulssin , but there do exist other power factions within the city . Church of Vhaeraun . Most Chaulssinyr give at least token obeisance to the sworn enemy of the Spider Queen . The church of Vhaeraun is led by Patron Father Xorthaul of Jachalkhyn and his clerics hold many influential positions among the Jaezred Chaulssin . However the other patron fathers subtly work against making the brotherhood into the sword arm of the church . When Lolth finally awoke after her silence they have moved to further distance themselves from the hierarchy of the Masked Lord , because they do not want to be between Lolth and her son in case of open warfare . Dark Bears . After their civilization collapsed at the end of the Deepbear Battles ( - 1803 DR to - 1350 DR ) , the quaggoth s of the Northdark reverted to a barbaric tribal society . The Deepkingdom declined and many quaggoth tribes fell under the domination of more powerful races , like the drow of Chaulssin . When the inhabitants of the city fled to the Plane of Shadow , they brought tribes of deep bear mercenaries with them . After the return of House Jaezred they brought descendants of these deep bears back to Faerûn . Now they were transformed into creatures of shadow , known as dark bears . They are organized in large tribes working as mercenary companies as front line defenders of the City of Wyrmshadows and patrol the surrounding Underdark . Shadar - kai . Small clans of Shadar - kai are found in cities across Faerûn , where they try to find a way against their grim fate . In the near past many members of this fey race came to Chaulssin , willingly exchanging their immediate freedom in exchange for magical aid in delaying their fate . Elite shadar - kai serve the Jaezred Chaulssin as spies , observing Lolth - worshipers in the Northdark . Most serve in teams of three or more under the command of a velve . Spider - kissers . Spider kisser is an epithet reserved among the Chaulssinyr for those suspected of worshiping Lolth . Most of them are slaves but it is also said that the Spider Queen has a handful of devotees among the Zar ' ihtra ' rin . Ilharen ' qarthen . Ilharen ' qarthen means commanding mothers and they are the harems of the Patron Fathers . They are exclusively female and serve the patron fathers for breeding . Most of them are Zar ' ihtra but one in five is a female drow slave of another city . All Ilharen ' qarthen rank above the other slave population of Chaulssin . Within the ranks of the harem exists another kind of hierarchy , one in which a female of dragon blood is placed above their full drow - blooded counterparts . Most of the Ilharen ' qarthen give birth to males , known as zekyl . The rare female child is slain at birth .