Juqu Mujian
In 436, after Emperor Taiwu had destroyed Northern Yan and seized its territory, he began to consider conquering Northern Liang. Still, in 437, he sent his sister Princess Wuwei to be married to Juqu Mujian. Juqu Mujian, although he was already married to Princess Li, felt compelled to accept, and Princess Wuwei became his princess. At the same time, Emperor Taiwu also ordered that Juqu Mujian's mother be honored as the Princess Dowager of Hexi. Juqu Mujian was forced to divorce Princess Li, who was exiled to Jiuquan from the Northern Liang capital Guzang (姑臧, in modern Wuwei, Gansu), and died soon thereafter. By Northern Wei demands, Juqu Mujian also sent Juqu Fengtan to the Northern Wei capital Pingcheng (平城, in modern Datong, Shanxi) as a hostage. However, he also continued to send messengers to Liu Song, offering tributes of books while requesting supplies of other books, and Emperor Wen granted them without question. (Despite the marriage, Emperor Taiwu considered launching a campaign against Northern Liang, but at the urging of Li Shun (李順), who had previously advocated military action as well but by this point was against such actions, arguing that the army was still tired from conquering Northern Yan and Xia as well as fighting Liu Song and needed rest, Emperor Taiwu postponed the plans.)