Pugu Huai'en
He was instrumental in the final suppression of the Anshi Rebellion, but rebelled against Emperor Daizong in fear that he was being accused of treason.
He successively served under two military governors (jiedushi) of Shuofang Circuit (朔方, headquartered in modern Yinchuan, Ningxia), Wang Zhongsi and An Sishun, and both were impressed by his ferocity in battle and knowledge about the other non-Han tribes, as well as command skills, and so gave him great responsibility.
During the subsequent campaign that Guo and Li Guangbi conducted against territory held by An Lushan north of the Yellow River, Pugu contributed to a number of victories.
Uyghurs' Bayanchur Khan gave a daughter to Li Chengcai in marriage, and returned him and Pugu with the proposal that he be allowed to marry a Tang princess.
In early 757, Guo made an attempt to recapture Chang'an from the east, but was defeated at Tong Pass.
When Shi Siming came to Yecheng's aid in summer 759, however, Tang forces collapsed, which the powerful eunuch Yu Chao'en blamed on Guo.
The general Zhang Yongji (張用濟) thus planned to expel Li Guangbi and demand Guo's return, but was persuaded not to act by Pugu.
In spring 761, this eventually turned into a disagreement where Pugu disagreed with Li Guangbi's strategy of holding at Heyang but rather advocated, along with Yu, that an effort should be made to recapture Luoyang.
Emperor Suzong agreed, and ordered Li Guangbi to advance toward Luoyang with Pugu, Yu, and Wei Boyu (衛伯玉).
Pugu changed Yaoluoge Yidijian's mind, and he instead agreed to attack Yan with Tang forces.
Several major Yan military governors, including Xue Song, Zhang Zhongzhi, Tian Chengsi, and Li Huaixian, surrendered to Tang with their forces.
[3]) As a result of Pugu's contributions, Guo, who at that time carried the nominal title of deputy supreme commander over forces north of the Yellow River (with Li Kuo being the nominal supreme commander), offered to transfer the title to him, and Emperor Daizong did so, also giving Pugu the additional nominal titles as Pushe (僕射) and chancellor (as Zhongshu Ling (中書令)).
Although Pugu Huai'en was the military governor of Shuofang, after the end of the Anshi Rebellion, he was stationed at Fen Prefecture (汾州, roughly modern Lüliang, Shanxi), with his son Pugu Yang and several other Shuofang generals under him, Li Guangyi (李光逸), Li Huaiguang, and Zhang Weiyue (張維嶽) stationed nearby.
Meanwhile, after the end of the campaign, Emperor Daizong had Pugu Huai'en escort Yaoluoge Yidijian through Hedong Circuit back to Uyghur; as they went through Hedong Circuit, Xin Yunjing again refused to meet them and refused to entertain them as host.
The eunuch Luo Fengxian (駱奉仙), serving as Emperor Daizong's messenger, was visiting Taiyuan, the headquarters of Hedong Circuit.
Pugu, in gratitude, asked Luo to stay an extra day to celebrate Duanwu Festival together.
At the suggestion of Yan Zhenqing and Lai Baoyu's cousin Li Baozhen (李抱真), Emperor Daizong publicly commissioned Guo Ziyi (who had been relieved of military commands for years but who earlier in the year had been put in charge of recapturing Chang'an after a Tibetan incursion briefly captured Chang'an and forced Emperor Daizong to flee) as the commander of Shuofang forces, hoping that the commission would cause Pugu's army to peel away from Pugu on its own.
(Emperor Daizong subsequently welcomed Pugu Huai'en's mother to Chang'an and treated her with respect until her death later in the year.)
Meanwhile, news came that Pugu had entered into an alliance with Tibet and Uyghur and were planning to attack Chang'an.
Emperor Daizong had Guo take up position at Fengtian (奉天, in modern Xianyang, Shaanxi) to defend against such potential attack.
