 Apparently, the Nizari Imam sought to at least keep the main Nizari strongholds, while the Mongols demanded the full submission of the Nizaris.In 19 November 1256, the Nizari Imam, who was in the Maymun-Dizh, surrendered the castle to the besieging Mongols under Hulagu Khan after a fierce conflict.Alamut fell in December 1256 and Lambsar fell in 1257, with Gerdkuh remaining unconquered.