Hubei) a renegade. Believing that neither Tan nor Wang Hong was involved in the plot to depose and kill Emperor Shao, he summoned them to the capital, and he put Tan in charge of the army to attack Xie. Xie, while a talented strategist, was unaccustomed to commanding large armies, and Tan defeated him; he was subsequently captured and executed. In light of his victory, Emperor Wen promoted Tan to greater titles and made him the governor of Jiang Province (江州, modern Jiangxi and Fujian). When Emperor Wen launched a major campaign against Northern Wei in 430 to try to regain provinces south of the Yellow River, Tan was not in command of the army—Dao Yanzhi () was. Dao was initially able to recover the provinces, as Northern Wei chose to abandon them temporarily, waiting for winter to counterattack. When it did so in winter 430, Dao retreated after Luoyang and Hulao fell, leaving Huatai (滑台, in modern Anyang, Henan) and its commanding general Zhu Xiuzhi () under Northern Wei siege and totally without support. Emperor Wen replaced Dao with Tan in spring 431, requesting that he try to advance to Huatai to save it. Tan was initially successful in his attempts to advance toward Huatai, winning several battles against Northern Wei forces. However, after he reached Licheng (歷城, in modern Jinan, Shandong), his supply route was cut off by the Northern Wei general Yizhan Jian (), and he was no longer able to reach Huatai. Huatai soon fell, Zhu was captured, and Tan retreated. On the way, Northern Wei forces became aware that Tan was out of food, and so trailed him, ready to attack. Tan then used a trick that made him famous in Chinese history—at night, he had the soldiers pretend that sand was grain and yell out the measurements, and then covered the sand with grain. In the morning, when Northern Wei forces saw the pile of sand covered with grain, they mistakenly thought that Tan's forces did not lack food at all, and therefore decided not to pursue him further. Tan was able to withdraw his forces without major losses. Emperor Wen gave him greater titles and returned him to Jiang Province. However, because of Tan's abilities and because his sons and subordinates were also all capable, he eventually became suspected by Emperor Wen and his brother, the prime minister Liu Yikang, particularly because Emperor