Siege of Menzoberranzan The Siege of Menzoberranzan was a siege of the drow city of Menzoberranzan by the combined forces of Horgar Steelshadow of Gracklstugh and Kaanyr Vhok ' s Scoured Legion with the secret backing of the Jaezred Chaulssin . Background . Slave uprising . During the Silence of Lolth , which began on Eleint 28 , 1372 DR , the goddess Lolth did not answer any of her supplicants , nor were her clerics able to cast any spells or otherwise use divine magic . Menzoberranzan , a matriarchal order ruled by Lolthite priestesses , was naturally in a perilous position . Priestesses were ordered by Matron Mother Triel Baenre not to speak of the Silence , but word nevertheless got out . A group of renegade male drow , led by the alhoon Syrzan ( likely with support from the Jaezred Chaulssin ) , instigated an uprising of slaves and " undercreatures " on Marpenoth 20 . This group , which used stonefire as a weapon , damaged the city and forced the slaughter of a large number of slaves . Battle of the Pillars of Woe . Soon after the slave revolt , the leaders of Menzoberranzan received word ( via Nimor Imphraezl of the Jaezred Chaulssin , who was posing as the drow captain Zhayemd of House Agrach Dyrr ) that Crown Prince Horgar Steelshadow had amassed a duergar army that was marching against the city . Nimor ' s warning instigated the creation of the Army of the Black Spider , a conglomeration of soldiers and slave fodder from two dozen drow houses . The army marched out to the Pillars of Woe , where they were ambushed by the duergar , who were joined by the tanarukk s of the Scoured Legion . In addition , the contingent of House Agrach Dyrr turned on their fellows , Matron Yasraena Dyrr and the Lichdrow Dyrr having made an alliance with the Jaezred Chaulssin . The drow army lost a fourth to a third of their total number ( which had been 4 , 000 drow and 2 , 500 slaves ) and were forced to retreat under cover of a rescue contingent sent by House Baenre . Siege of Menzoberranzan . On Uktar 3 , 1372 DR , Kaanyr Vhok and the forces of Gracklstugh ( more than 5 , 000 duergar in more than eight companies , with orc and ogre slaves ) began besieging Menzoberranzan itself . The forces approached from the southeast , and also swung around and attacked from the north , utilizing a tunnel from outside the city that gave access to Tier Breche where the Academy was located . This remained the main battlefield for quite some time , which the masters of the Academy working together to prevent the besiegers from overtaking the city . The attackers used stonefire to damage the Academy ' s structures ; they were damaged but remained intact at the end of the siege . In addition , the duergar armies raised undead soldiers to fight from them . At least once , the Archmage of Menzoberranzan was able to turn the undead soldiers against their fellows . Just before the siege began , Gromph Baenre , the Archmage , had been missing for a period of several weeks after being imprisoned by the Lichdrow Dyrr . He returned to find the city under siege and he took it upon himself to remove Nimor Imphraezl from the picture . He gathered all the mages of House Baenre and attempted to attack Nimor through a scrying crystal . However , Nimor ' s protections reflected the spells cast upon him , killing Julani Baenre and injuring the other wizards . Gromph then disguised himself and weaponsmaster Andzrel Baenre as tanarukks of the Scourged Legion and entered the enemy camp . Gromph attached a light gem to Nimor to prevent him shadow - walking . Nimor transported himself to the Plane of Shadow , but was stuck there for some time , unable to shadow - walk back to the Material Plane . At the same time that the city was besieged by outside forces , House Xorlarrin , with some support from other houses , was besieging the traitorous House Agrach Dyrr . Gromph Baenre also confronted the Lichdrow Dyrr in a spell battle that destroyed the Bazaar . The Jaezred Chaulssin also attempted an assassination attempt on Triel Baenre , which failed . On Ches 28 , 1373 DR , the Silence of Lolth ended and Lolth ' s priestesses regained their powers . Kaanyr Vhok subsequently recalled his forces to Hellgate Keep ; the remaining duergar were easily defeated and turned back . The siege officially ended on Ches 30 . Aftermath . All in all , Vhok lost 120 tanarukks in the Siege of Menzoberranzan . There was an unknown - - but surely much greater - - number of duergar , drow , and slave casualties . As the duergar army retreated , Nimor swept in and killed Horgar Steelshadow . He spoke with Vhok , ensuring that the Scoured Legion and the Jaezred Chaulssin could still be potential allies in the future . Soon after the siege had ended , life in the city had mostly returned to normal . The inhabitants were in the process of rebuilding the damage with the help of the captured duergar , which had become slaves . House Agrach Dyrr was spared , except for the temple , which was destroyed when Gromph Baenre inadvertently activated the master ward while destroying the phylactery of the Lichdrow . Triel Baenre arrived and halted the Xorlarrins ' assault , meeting with Anival Dyrr and forming an agreement : House Agrach Dyrr was to become a vassal of House Baenre for centuries , " essentially an extension of House Baenre . "