Li Cunshen
However, Jin was soon challenged by the Khitan Empire to the north as well, with Khitan's Emperor Taizu (Yelü Abaoji) launching a major attack on Lulong in 917, putting You Prefecture under siege. While Li Cunxu and his generals (his adoptive brothers Li Siyuan and Li Cunshen, as well as Yan Bao () subsequently repelled the Khitan attack, Lulong's vulnerability to Khitan attacks had been exposed, and in the future, there would be recurrent Khitan incursions against Lulong.