Siege of Samarkand (1220)

While medieval chroniclers have attributed huge forces to both sides, modern historians are more conservative in their estimates, but precise numbers are still widely disputed; the only certainty is that the total Mongol force was larger than the Shah's army.^[3]: 113 The Shah, who distrusted his commanders and had not yet implemented his desired methods of administration, decided on a strategy of distributing troops inside his major cities, such as Samarkand, Balkh and Otrar.^{[4]: 31 [5]: 373–380} It is likely that he expected only a "normal-sized" Mongol raid, which would devastate the countryside but leave the cities unharmed.^[6]: 150 The Khwarazmids would only previously have fought nomads such as the Kangly, who had no knowledge of siege warfare; that these invaders were bringing a veritable army of engineers who were skilled in siege warfare came as a great shock.^[7]: 89 In any event, estimates for the city's garrison vary widely.^[8]

The first attack on the Khwarazmian Empire made by the Mongols was at the town of Otrar, whose governor had made the grievous mistake of insulting the Khan. This border city, however, was able to hold out for a surprising length of time, and so Genghis made the decision to split his forces to try to outmanoeuvre the Shah. He had learnt of the strength of Samarkand's defences at Otrar, and thus made the decision to march through the Kizil Kum desert to Bukhara.^[9] The city was stunned by the Mongol approach, which had been through an area previously thought impassable, and, after a sortie was annihilated along the Amu Darya, the lower town surrendered and was promptly pillaged. The inner citadel held out for less than two weeks, but after the Mongols breached the walls, all inside were massacred.^{[10]: 103–107} Unlike during later campaigns, the Mongols were comparatively lenient with the citizens of Bukhara; however, a large number were conscripted to be used in the following sieges.^[11]

After the fall of Bukhara, Chinggis Khan advanced along the Zarafshan valley toward Samarkand, one of the most significant cultural and commercial centers of Transoxiana. Positioned between Samarkand, Balkh, and Urganj, his maneuver divided the forces of Muhammad. The city was well-fortified with eight iron gates and defended by approximately 30,000 Qanquli Turkmen and 50,000 local forces under governor Taghday Khan, brother of Turkan Khatun. The garrison also included 20 war elephants. According to Dupuy, Samarkand had a garrison of reportedly 100,000 men. Genghis Khan reached the city in March 1220 and was joined there by his sons, whose forces had previously completed the capture of Otrar. The Mongols encircled Samarkand and repelled a sortie involving the elephants and a cavalry force, killing roughly 1,000 defenders. A large portion of the garrison surrendered on 16 March, leaving only the citadel, defended by about 2,000 soldiers. After one month, a final sortie allowed 1,000 men to escape across the Amu Darya, while the remaining surrendered garrison of approximately 3,000 was executed. Captured elephants released into the countryside quickly died.^{[2][12][13][14]}