Mongol Siege Engine System

Timeline

1. 1205–1210Hetao and Ningxia border · NorthwestIn the course of campaigns against Western Xia, the Mongol army captured and conscripted Han, Western Xia, and Western Regions craftsmen, seizing trebuchets, scaling ladders, and other engines, and began incorporating siege equipment into army logistics, accumulating technology and manpower for the large-scale war against Jin.
2. 1211–1214Outskirts of Jin's Xijing (present-day Datong) · ShanxiIn 1211 the Mongol army attacked Jin along several routes, using scaling ladders, stone-throwing machines, and fire attacks in combination with mounted archery to besiege cities such as Xijing and Xuande; despite resistance from Jin firearms like the Zhentianlei thunderclap bombs, siege engines had become standard equipment for expeditions, showing that the Mongol siege model was taking shape.
3. 1215Jin Zhongdu · North ChinaIn 1215 the Mongol army besieged Jin's Zhongdu, bombarding walls and towers with giant trebuchets, combined with tunnels, scaling ladders, and fire attacks, finally breaching the city; this marked that the Mongol siege engine system could handle first-rate North China defenses and also prompted the Jin dynasty to move its capital.
4. 1216–1220Battlefields of North China cities · North ChinaFrom 1216 to 1220 the Mongol army mopped up remnant Jin forces in North China; siege engines moved with the army, and surrendered craftsmen manufactured and repaired trebuchets, ballistae, and siege towers on site according to Mongol needs, with the system tending toward standardization, providing experience for later sieges in Central Asia during the western campaigns.