crown prince. Over the years, because of Du's mistreatment of the soldiers, the soldiers, lacking food and clothing, were forced to pillage the borders of Nanzhao in order to have sufficient supplies. Nanzhao reacted by giving gifts of clothing and food to these Tang soldiers in exchange for information about Xichuan Circuit. As a result, Nanzhao became highly aware of Xichuan's vulnerabilities. By 829, at which time Emperor Jingzong's brother Emperor Wenzong was emperor, the Nanzhao prince Mengcuodian (蒙嵯顛) was planning a major attack against Xichuan. When the border prefectures received rumors of Mengcuodian's plans, their warnings to Du were unheeded, and thus, when Mengcuodian, guided by Xichuan soldiers who resented Du, launched his attack, he encountered no resistance, quickly capturing Xi (雟州, in modern Liangshan Yi Autonomous Prefecture, Sichuan) and Rong (戎州, in modern Yibin, Sichuan) Prefectures. Du sent forces to resist Mengcuodian, but after Mengcuodian defeated Xichuan forces, Qiong Prefecture fell to Nanzhao as well. Nanzhao forces put Chengdu under siege and entered its western city, while forward troops reached as far as Zi Prefecture (梓州, in modern Mianyang, Sichuan), the headquarters of Xichuan's neighboring circuit Dongchuan (東川). Nanzhao forces stayed at Chengdu's western city for 10 days before pillaging Chengdu and withdrawing, taking with them tens of thousands of Xichuan craftspeople and young men and women. It was said that after this incident, Nanzhao had crafts capabilities rivaling Xichuan. Emperor Wenzong initially demoted Du to be the prefect of Shao Prefecture (邵州, in modern Shaoyang, Hunan). After Mengcuodian submitted a petition accusing Du of crimes and explaining the reasons for the incursion, and further demanding Du's execution, Emperor Wenzong further demoted Du to be the military advisor to the prefect of Xun Prefecture (循州, in modern Huizhou, Guangdong). Subsequently, the military governor of Dongchuan, Guo Zhao (郭釗), was made the military governor of Xichuan and made peace with Nanzhao. Several of Du's key staff members were likewise demoted. Du died in 833 at Xun Prefecture. Before he died, he submitted a petition begging for posthumous restoration to a higher office, and Emperor Wenzong awarded him a posthumous promotion to prefect. Du Yuanying's nephew Du Shenquan (Du Yuanjiang's son) and Du Shenquan's son Du Rangneng later served as chancellors as well. Notes and references Old Book of Tang, vol. 163. New Book of Tang, vol. 96. Zizhi Tongjian, vols. vol. 241, 242, 243, 244. 769 births 833 deaths