Yuchi Jingde - During Emperor Taizong's Reign

During Emperor Taizong's Reign

Two months after the Incident at Xuanwu Gate, Emperor Gaozu yielded the throne to Li Shimin, who took the throne as Emperor Taizong. Later that year, when Eastern Tujue's Jiali Khan Ashina Duobi launched a major attack against Tang, Yuchi was one of the generals sent to resist Eastern Tujue; he was able to defeat and kill an Eastern Tujue general that he faced. (Ashina Duobi, however, was able to penetrate all the way to the Tang capital Chang'an, forcing Emperor Taizong to personally meet him and promising large tributes before withdrawing.) Late in 626, Emperor Taizong created Yuchi Jingde the Duke of Wu and gave him, Zhangsun Wuji, Fang Xuanling, and Du Ruhui the largest fiefs among his supporters.

Meanwhile, Yuchi, who was known for being blunt, was proud of his achievements. Whenever he disagreed with Zhangsun, Fang, and Du (all of whom were made chancellors by Emperor Taizong), he would argue with them bitterly, and thus had poor relationships with them. In 629, Yuchi was made the commandant at Xiang Prefecture (襄州, roughly modern Xiangfan, Hubei). In 634, he was made the prefect of Tong Prefecture (同州, roughly modern Weinan, Shaanxi), a nominal demotion but considered a promotion as it was close to Chang'an. On one occasion, when he attended a feast held by Emperor Taizong at Qingshan Palace (慶善宮, in modern Xianyang, Shaanxi), another person, probably Yuwen Shiji, was seated above him, and Yuchi angrily stated, "What achievement do you have that you get to be seated above me?" Li Daozong, who was seated under Yuchi, tried to intercede, and Yuchi, in anger, punched Li Daozong, almost blinding him. Emperor Taizong was displeased and ended the feast early, and thereafter warned yuchi:

I greatly hated Emperor Gao of Han for his massacre of those with achievements, and I wanted to maintain my honor and glory with you and your descendants for generals. But you, even though you are a governmental official, continue to commit crimes, and I now see that it was not Emperor Gao's fault that Han Xin and Peng Yue had their flesh ground into bits. The order of the state is maintained by awards and punishments. My grace toward you cannot be perpetual. You need to examine yourself and change yourself before it is too late.

Only thereafter did Yuchi began to fear Emperor Taizong and start to modify his behavior. In 637, as part of Emperor Taizong's scheme to bestow prefectures on his relatives and great generals and officials as their permanent domains, Yuchi's title was changed to Duke of E, and he was given the post of prefect of Xuan Prefecture (宣州, roughly modern Xuancheng, Anhui), to be inherited by his heirs. Soon, however, with many objections to the system, the strongest of which came from Zhangsun Wuji, Emperor Taizong cancelled the scheme, although Yuchi's title remained Duke of E. He subsequently served two different terms as commandant. In 643, he offered to retire, and the retirement was granted, but Emperor Taizong still requested that Yuchi attend imperial gatherings once every five days. Later that year, when Emperor Taizong commissioned the Portraits at Lingyan Pavilion to commemorate the 24 great contributors to Tang rule, Yuchi's was one of the portraits commissioned.

In 645, when Emperor Taizong wanted to personally attack Goguryeo, Yuchi submitted a petition opposing it, arguing that he should just send generals and not go himself, lest that someone rises against Emperor Taizong's crown prince Li Zhi. Emperor Taizong did not agree, and instead had Yuchi follow him on the campaign, apparently as a consultant. After the end of the campaign, Yuchi returned to retirement.

It was said that late in his life, starting from around 642, Yuchi became an adherent to Taoist alchemy, and regularly consumed mica. He also lived luxuriously within his mansion but did not take in visitors, instead spending time enjoying Qingshang (清商樂), a musical style said to originate from Cao Cao.