of great powers to Yin Jingren, Liu Zhan () became to try to defame Yin Jingren, and he ingratiated himself with Liu Yikang to try to use the prime minister's powers to expel Yin from government. Yin, not willing to fight Liu Zhan, offered to resign under the excuse he was ill, and while Emperor Wen refused, he permitted Yin to take an extended sick leave. The imperial government, however, became divided into a Liu Zhan-led pro-Liu Yikang faction and an anti-Liu Yikang faction. In 436, Emperor Wen grew extremely ill. In his illness, Liu Zhan persuaded Liu Yikang that if Emperor Wen died, no one would be able to control Tan Daoji, and therefore recalled Tan to the capital from his post at Jiang Province (江州, modern Jiangxi and Fujian). After Tan arrived at Jiankang, Emperor Wen became better in his conditions and was ready to return Tan to his post, when he suddenly turned ill again. At that time, Tan was already on the dock ready to depart for Jiang Province, and Liu Yikang summoned him back to Jiankang and arrested him. Emperor Wen then issued an edict falsely accusing Tan of preparing treason and executed him with his sons, but spared his grandsons. (When Tan was arrested, he angrily threw his scarf on the ground and stated bitterly, "You have destroyed your Great Wall." When Northern Wei officials heard of Tan's death, they celebrated. The traditional account appeared to minimize Emperor Wen's involvement in Tan's death, but subsequent events appear to show that Liu Yikang acted with Emperor Wen's full approval in this matter.) In spring 437, Emperor Wen seriously considered the proposal that Northern Wei's Emperor Taiwu had made, initially in 431 and then in 433, that the two imperial clans enter into a marital relationship—specifically, to marry one of his daughters to Emperor Taiwu's crown prince Tuoba Huang, and he sent his official Liu Xibo () to Northern Wei to negotiate the terms of the marriage. However, soon thereafter, the daughter who was to marry Tuoba Huang died, and the proposal died with her. Later in 437, the long-term rebel Cheng Daoyang the Prince of Shu was finally captured and killed, ending a seven-year rebellion. In 438, Emperor Wen built a university to encourage students to study famous works. He set up four disciplines at the university: Mysticism, taught by the official He Shangzhi ()