Campaign against Quhistan, Qumis, and Khurasan , from a manuscript of '''' by
Hayton of Corycus. The garrison resisted for 17 years, long after the surrender of the Nizari leaders. In March 1253,
Hülegü's advance guard under the command of
Kitbuqa crossed the Oxus (
Amu Darya) with 12,000 men (one
tümen plus two
mingghans under
Köke Ilgei). In April 1253, they captured several Nizari fortresses in
Quhistan and killed their inhabitants, and in May they attacked the district of
Qumis and laid siege to
Gerdkuh, the main Nizari stronghold there. His army consisted of 5,000 (probably Mongol) cavalrymen and 5,000 (probably
Tajik) infantrymen. Kitbuqa left an army under
amir Büri to besiege Gerdkuh, and himself attacked the nearby Mihrin (
Mehrnegar) castle and Shah (in
Qasran?). In August 1253, he sent raiding parties to the Tarem and Rudbar districts with little results. Afterward they attacked and slaughtered the inhabitants of Mansuriah and Alabeshin (Alah beshin). In October 1253, Hülegü left his
orda in Mongolia and began his march with a
tümen at a leisurely pace and increased his number in his way. In July 1253, Kitbuqa who had been in Quhistan, pillaged, slaughtered, and seized probably temporarily
Tun (
Ferdows) and
Turshiz. A few months later,
Mehrin and several other castles in Qumis fell as well. In September 1255, Hülegü arrived near
Samarqand. All of the rulers of Rum (
Anatolia),
Fars,
Iraq,
Azerbaijan,
Arran,
Shirvan,
Georgia, and supposedly also
Armenia, acknowledged their service with many gifts. As Hülegü reached
Bistam, his army had enlarged into five
tümens, and new commanders were added. Many of them were the relatives of
Batu Khan. From the
ulus of
Jochi representing the Golden Horde came Quli (son of
Orda), Balagha, and Tutar. The
Chagatai Khanate forces were under
Tegüder. A contingent of
Oirat tribesmen also joined under
Buqa Temür. No member of
Ögedei's family is mentioned. Hülegü had with him a thousand squads of
siege engineers (probably north
Chinese,
Khitan and Muslim) skilled in the use of
mangonels and
naphtha. The right wing, under Buqa Temür and Köke Ilgei, marched via
Tabaristan. The left wing, under Tegüder and Kitbuqa, marched via
Khuwar and
Semnan. The center was under Hulegu himself. Meanwhile, Hülegü sent another warning to Khurshah. Khurshah was at the
Maymun-Diz fortress and was apparently playing for time; by resisting longer, the arrival of winter could have stopped the Mongol campaigning. He sent his vizier Kayqubad; they met the Mongols in
Firuzkuh and offered the surrender of all strongholds except Alamut and Lambsar, and again asked for a year's delay for Khurshah to visit Hülegü in person. Meanwhile, Khurshah ordered Gerdkuh and the fortresses of Quhistan to surrender, which their chiefs did, but the garrison of Gerdkuh continued to resist. The Mongols continued to advance and reached
Lar,
Damavand, and
Shahdiz. Khurshah sent his 7- or 8-years-old son as a show of good faith, but he was sent back due to his young age. Khurshah then sent his second brother Shahanshah (Shahin Shah), who met the Mongols at
Rey. But Hülegü demanded the dismantling of the Nizari fortifications to show his goodwill.
Capitulation of Alamut depicting Hülegü and the Mongols dismantling Alamut Khurshah instructed all Nizari castles of the Rusbar valley to capitulate, evacuate, and dismantle their forts. All castles (around forty) subsequently capitulated, except
Alamut (under
sipahsalar Muqaddam al-Din Muhammad Mubariz) and
Lambsar, possibly because their commanders thought the Imam had issued orders under duress and was practicing a sort of
taqiyya. Despite the small size of the fortress and its garrison, Alamut was stone-built (unlike Maymun-Diz), well-provisioned, and featured a reliable water supply. However, the Nizari faith demands the faithful pay absolute obedience to the
Imam in all circumstances. Hülegü surrounded Alamut with his army, and Khurshah unsuccessfully attempted to persuade its commander to surrender. Hülegü left a large force under Balaghai to besiege Alamut, and himself together with Khurshah set out to besiege the nearby Lambsar. Muqaddam al-Din eventually capitulated when he learned that the Imam wasn't obligated to surrender after a few days in December 1256. Juvayni describes the difficulty by which the Mongols dismantled the plastered walls and
lead-covered ramparts of Alamut. The Mongols had to set fire to the buildings and then destroy them piece by piece. He also notes the extensive chambers, galleries, and deep tanks, replete with wine, vinegar, honey, and other goods. During the pillage, one man was almost drowned in a honey store. After examining Alamut's famous library, Juvayni saved "copies of the Qur'an and other choice books" as well as "astronomical instruments such as
kursis (part of an
astrolabe),
armillary spheres, complete and partial astrolabes, and others", and burned the other books "which related to their heresy and error". He also picked
Hasan Sabbah's biography,
Sargudhasht-i Bābā Sayyidinā (), which interested him, but he claims he burnt it after reading it. Juvayni has extensively cited its contents in his
Tarikh-i Jahangushay. Juvayni noted the impregnability and self-sufficiency of Alamut and the other Nizari fortresses. Rashid al-Din similarly writes of the good fortune of Mongols in their war against the Nizaris. ==Massacres of the Nizaris==