supply trains were required. The Southern Tang military utilized a combination of infantry and naval forces, while cavalry was seldom employed. However, in the open Central Plains cavalry forces held the advantage. Peter A. Lorge concluded that these circumstances made Southern Tang campaigns into the Central Plains logisitically challenging. Hino Kaisaburō has detailed the principle routes used for inland economic and diplomatic exchanges between northern and southern Chinese states. These were the Grand Canal, Gan River, and Xiang River. Control of the Grand Canal was divided between several states, therefore it was the least used route in the era. Later Jin In 936 Shi Jingtang secured an alliance with the Yelü Deguang to overthrow his brother-in-law Li Congke of the Later Tang with Khitan forces. He ceded the Sixteen Prefectures, promised annual tribute, and accepted a subordinate role to Yelü Deguang. In return the Khitan ruler appointed Shi Jingtang as Emperor of the Later Jin. Throughout his reign Shi Jingtang maintained amicable relations with his overlord, despite criticism from many officials. In the summer of 938 Song Qiqiu proposed for the assassination of a Khitan dignitary that was visiting the Southern Tang court when they returned north through Later Jin territory. He felt that the murder could provoke a war between the Later Jin and the Khitans. While successful in killing the envoy, the harmonious relations between the Later Jin and Khitan continued. In 940 the Southern Tang supported backed a rebellion in the Later Jin territory Anyuan. Li Bian broke his policy of maintaining peaceable relations with neighboring states in a campaign that ultimately ended in Southern Tang failure. The military commissioner of Anyuan, Li Jinquan, contacted the Southern Tang with an offer to change allegiance from the Later Jin to the Southern Tang realm. Li Bian accepted the offer and sent an army northwards. Southern Tang forces met up with Li Jinquan as planned. But against Li Bian's commands its commanders ordered the looting Anlu. Afterwards, the Southern Tang army began to return home. Later Jin forces eventually caught up to the sluggish Southern Tang army and decisively defeated them in Mahuang Valley. The disobedience of his commanders upset Li Bian greatly. In a letter to Shi Jingtang, he claimed his generals were uncontrollable, as they were keen on career advancement through combat, and pressed for amicable relations. Thus, ended Southern Tang pretensions to the Central Plains for