Later Liang proper) and collect taxes from the tea trade for military use. Ma agreed. He thus, with approval from Emperor Taizu, established tea trade offices at the Later Liang capital Daliang, as well as at Jing Prefecture (荊州, Jingnan's capital), Xiang Prefecture (襄州, in modern Xiangyang, Hubei), Tang Prefecture (唐州, in modern Zhumadian, Henan), Ying Prefecture (郢州, in modern Jingmen, Hubei), and Fu Prefecture (復州, in modern Tianmen, Hubei). Under this scheme, Chu tea would be shipped to the north and sold; the proceeds would be used to purchase silk and horses, which were lacking in the south. Part of the tea shipment was given to the Later Liang imperial government as tribute. It was said that under this scheme, Chu began to become a wealthy state. Meanwhile, Ma encouraged commerce within the Chu state by not taxing commercial transactions. As a result, merchants from everywhere came to Chu to conduct their commerce. In order to take advantage of this phenomenon, Gao, as of 925, suggested to Ma that he mint coins out of two metals not usually used for minting—lead and iron. The Chu money would not be useful in other states, so the merchants were forced to purchase goods within Chu before leaving. This allowed Chu to be able to trade its goods for goods that it lacked, allowing it to become even wealthier. Over the years, Ma continued to trust Gao's advice, and the other states despised Gao's abilities. After Later Liang was destroyed by Later Tang in 923, Ma became a vassal of Later Tang, and sent his son Ma Xifan to pay tribute to Later Tang's Emperor Zhuangzong. Emperor Zhuangzong, while praising Ma Xifan for his intelligence and alertness, chose to try to sow the seeds of dissension by stating, "I had long heard that the Ma state would be seized by Gao Yu. With a son like you, how could Gao steal the state?" Gao Jixing, who by 929 was the ruler of a separate state of Jingnan to Chu's north, also tried to create suspicions by spreading rumors against Gao Yu, but Ma Yin paid no heed to these rumors. Gao Jixing then sent a letter to Ma's second eldest son Ma Xisheng, whom Ma Yin had by that point put in control of most affairs of the Chu state, ostensibly to seek permission to allow him to enter into a blood