The subsequent capitulation of the symbolic stronghold of Alamut marked the end of the Nizari state in Persia.

In the narration, it mostly focuses on the performance of the Chinese general Guo Kan who allegedly devised a new siege engine to attack the unusual fortification of Maymun-Diz.

[5] Hülegü had with him a thousand squads of siege engineers (probably north Chinese, Khitan and Muslim) skilled in the use of mangonels and naphtha.

Khurshah was in the Maymun-Diz fortress and was apparently playing for time, because by resisting longer, the arrival of winter could have stopped the Mongols whose military was dependant on available fodder for their horses.

[12] Maymun-Diz could have been attacked by mangonels; this was not the case with Alamut, Nevisar Shah, Lambsar and Gerdkuh, all of which were on top of high peaks.

The Mongols then used heavier siege engines hurling javelins dipped in burning pitch and set up additional mangonels all around the fortifications.

After several days, Hülegü began another round of bombardment and on November 19, Khurshah and his entourage descended from the fortress and capitulated.

[7][8][13] According to the History of Yuan, the Chinese general Guo Kan attacked the fortress by "catapults on mounts" (jiapao).

[15] An inexplicable aspect of the events for historians is that why the forces at Alamut made no effort to assist their besieged comrades in Maymun-Diz.

[16] The subsequent capitulation of the garrison of Alamut Castle, also outnumbered but well-provisioned, marked the official end of the Nizari state in Persia.