Yang Yichen (Sui Dynasty) - During Emperor Yang's Reign

During Emperor Yang's Reign

In 604, Emperor Wen died -- a death that traditional historians, while admitting a lack of direct evidence, generally believe to be a murder ordered by his son, Yang Guang the Crown Prince. Yang Guang took the throne as Emperor Yang. Soon afterwards, Emperor Yang's younger brother Yang Liang the Prince of Han rose in rebellion at Bing Province (并州, roughly modern Taiyuan, Shanxi). Yang Liang's general Qiao Zhongkui (喬鍾葵) afterwards put Li Jing (李景), the commandant of Dai Province (代州, roughly modern Xinzhou, Shanxi), who remained loyal to Emperor Yang, under siege. Emperor Yang ordered Yang Yichen to try to lift the siege against Li, and Yang Yichen was successful in defeating Qiao. After Yang Liang was defeated and forced to surrender to Yang Su, Yang Yichen was given material rewards and made the governor of Xiang Province. In 607, Emperor Yang recalled him to be the director of imperial clan affairs, and later the director of husbandry affairs.

In 609, Yang Yichen served as a general in the largely successful campaign against Tuyuhun. In 612, he also served in Emperor Yang's first campaign against Goguryeo, commanding part of the force under Yuwen Shu the Duke of Xu that aimed to penetrate deep into Goguryeo territory, against its capital Pyongyang. While Yang Yichen was personally successful, the campaign was itself a major failure, and as a result, Yang Yichen was removed from his post. However, Emperor Yang soon restored him, and in 613, when Emperor Yang launched a second campaign against Tuyuhun, Yang Yichen again served under Yuwen in an attempt to attack Pyongyang, but when news arrived that Yang Su's son Yang Xuangan had rebelled near the eastern capital Luoyang the campaign was abandoned. Afterwards, with much of Sui territory engulfed in agrarian rebellions, Yang Yichen was sent against the rebel leader Xiang Haiming (向海明), who had claimed imperial title near Chang'an, and Yang Yichen defeated Xiang.

In 616, Emperor Yang sent Yang Yichen against another major rebel leader, Zhang Jincheng (張金稱), and Yang, after lulling Zhang into a sense of security, defeated him and forced him to flee, allowing another Sui general, Yang Shanhui (楊善會), to capture and execute Zhang. Yang Yichen then engaged another major rebel leader, Gao Shida (高士達), who had claimed the title of Duke of Donghai. Around the new year 617, Gao, going against the advice of his subordinate Dou Jiande, engaged Yang Yichen, and Yang Yichen defeated and killed Gao and nearly captured Dou. However, believing that Dou to not pose a further threat, he did not pursue Dou further.

Meanwhile, Emperor Yang and the prime minister Yu Shiji had become suspicious of Yang Yichen after his victories. Emperor Yang summoned Yang Yichen to his then-location at Jiangdu (江都, in modern Yangzhou, Jiangsu) and, ostensibly promoting him, made him the minister of ceremonies, while disbanding his troops. Yang Yichen died soon afterwards.