Series of Campaigns in the Song-Mongol War

Timeline

1. 1240–1241Song-Mongol border · ChinaAfter Jin's fall in 1234, Song and Mongol quickly fell out over the ownership of Henan and border defense treaties. Around 1240, the Mongols took Henan, the Huai region, and Sichuan as directions of attack, while the Southern Song relied on veteran generals like Meng Gong to shore up Jinghu defenses; the two sides moved from probing clashes to full-scale war.
2. 1241–1246Henan and Sichuan · ChinaMongol princes and commanders advanced south along separate routes: the northern front attacked Luoyang, Xiangfan and other key positions, while the western front pushed deep into Ba-Shu. Southern Song's Yu Jie became Pacification Commissioner of Sichuan in 1241 and implemented a mountain-fortress defense system; Meng Gong consolidated the Xiangyang-Jiangling line. Fighting ebbed and flowed with victories and defeats on both sides.
3. 1244–1249Southwest frontier · YunnanTo outflank the Southern Song, the Mongols applied military and diplomatic pressure on the Dali Kingdom. An envoy incident in 1244 intensified their conflict, and the southwest situation became interlinked with the Central Plains and Sichuan theaters. By the end of the 1240s, the Song-Mongol War had become a prolonged war of attrition, laying the groundwork for larger-scale conquests in the 1250s.