Mongol Siege Engineering System

Timeline

1. c. 1201–1205Fortresses around the Mongolian steppe · Mongolian PlateauDuring the unification of Mongolia, the army occasionally besieged fortresses held by hostile tribes, gaining initial exposure to siege operations, but engineering equipment and skilled craftsmen remained very limited.
2. c. 1206–1209Western Xia border (present-day Ningxia–Inner Mongolia) · Western XiaAfter 1206, in order to take Western Xia's fortified cities, the Mongol army began systematically recruiting surrendered craftsmen from the Central Plains and Western Xia, forming mobile engineering teams that used trebuchets, scaling ladders, and fire attacks to besiege prefectural cities.
3. c. 1209–1210Western Xia capital Zhongxingfu (present-day Yinchuan) · NingxiaIn 1209 Mongol prince Tolui led troops to besiege Western Xia's main forces, using trebuchets to batter walls, driving captives to fill moats, and employing flooding; although he could not fully take the city, he forced Western Xia to pay tribute, validating the combat effectiveness of the siege engineering system.
4. c. 1211–1250Siege battlefields from Central Asia to North China · East AsiaDuring the destruction of Jin and the western campaigns, the Mongol army widely absorbed Persian and Central Asian craftsmen, using counterweight trebuchets (Huihui pao) to take Samarkand, Baghdad, and the strongholds of the Central Plains, bringing the siege engineering system to maturity.