杜佑
Later, Zhang Jianfeng the military governor ("Jiedushi") of Xusihao Circuit (徐泗濠, headquartered in modern Xuzhou, Jiangsu) invited Li to serve on his staff. In or before 800, when Zhang grew ill, one of his subordinates, Du Jian (杜兼) the prefect of one of Xusihao's prefectures, Hao Prefecture (濠州, in modern Chuzhou, Anhui), was plotting to succeed Zhang, and therefore, without Zhang's orders, arrived at Xusihao's capital Xu Prefecture (徐州). Li rebuked him and stated that if Du did not return to Hao Prefecture immediately, he would report this to the imperial government; Du, in fear, did so. When Zhang died in spring 800, the imperial government initially was set to commission Wei Xiaqing (韋夏卿) to succeed him, but the Xu Prefecture forces rebelled and supported Zhang's son Zhang Yin (張愔) as his successor. After forces commanded by Du You the military governor of Huainan Circuit (淮南, headquartered at Yang Prefecture) and Zhang Pi (張伾) the prefect of Si Prefecture (泗州, in modern Huai'an, Jiangsu) were both defeated by Xu Prefecture troops, the imperial government capitulated and allowed Zhang Yin to become military prefect (團練使, "Tuanlianshi") of Xu Prefecture but took the other two prefectures and merged them into Huainan Circuit.