Yu Jie's Luochuan Defense

Timeline

1. 1241Chongqing · ChongqingIn 1241, Yu Jie was appointed Sichuan pacification commissioner, taking charge of military and civil affairs in Sichuan. Facing sustained Mongol pressure, he abandoned plain-based defense, advocated building forts at strategic strongpoints with linked garrisons, and moved the commissioner's office to Chongqing to coordinate defenses along the Jialing and Yangtze rivers.
2. 1241–1242Diaoyu Mountain, Luochuan, Fuzhou · ChongqingYu Jie built mountain fortresses such as Diaoyu Fortress around Luochuan in Fuzhou, using the terrain to control the junction of the Fu and Jailing rivers. With deep ditches, high walls, and ample grain and weapons, these forts formed a network of positions able to hold independently and support each other, effectively checking Mongol penetration into the Sichuan Basin.
3. 1242–1243Fuzhou mountain-fortress line · ChongqingThe Mongols repeatedly attacked the Fuzhou mountain-fortress line but could not take it owing to the steep terrain and stubborn defenders. The Luochuan defense system became the pillar of Southern Song resistance in Sichuan, greatly draining Mongol strength and buying strategic buffer to preserve the Yangtze upper-reach barrier.