According to traditional historians, Emperor Yizong did not pay much attention to governmental affairs but instead chose to live in opulence, became an alcoholic and surrounded himself with women while his government levied heavy taxes on its citizens.

Extreme hardships, including famines that forced people to resort to cannibalism, led to widespread agrarian rebellions late in his reign.

By 859, as a side effect of those pills, he had a large ulcerous boil on his back, such that he was bedridden and could not meet with the chancellors or other officials.

[3][8] Meanwhile, the agrarian rebel Qiu Fu (裘甫) and his followers were overrunning Zhedong Circuit (浙東, headquartered in modern Shaoxing, Zhejiang).

[3][8] Qiu's rebellion was suppressed by the imperial general Wang Shi in 860, but the Dali attacks would become more intense, and Dali briefly captured the important city Yong Prefecture (邕州, in modern Nanning, Guangxi) in 861 and then captured Jiao Prefecture (交州, in modern Hanoi, Vietnam) in 862, retaining it.

Despite these crises, Emperor Yizong was said to be spending much of his time in feast and games, ignoring the affairs of state, despite his officials' urging to attend to them, although he was sending generals to the Dali front (including Kang Chengxun and Gao Pian), without initial success.

[3] Meanwhile, though, the tense situation on the Dali border at Xichuan Circuit (西川, headquartered in modern Chengdu, Sichuan) led to a major misstep on the part of Emperor Yizong, as he was misled by the official Li Shiwang (李師望) into carving out seven border prefectures out of Xichuan into a new Dingbian Circuit (定邊, headquartered at Xi Prefecture (巂州), in modern Chengdu) and commissioning Li Shiwang as its military governor despite the obvious impractical nature of Dingbian's territory—as Xi Prefecture was extremely close to Xichuan's capital Chengdu Municipality and unsuitable to serve as the capital for a circuit intended to concentrate on border defense.

Not until Kang Chengxun, with major assistance from the Shatuo chieftain Zhuye Chixin (who was bestowed the imperial surname of Li, as well as a new name of Guochang because of his contributions), was able to defeat Pang in 869 was the rebellion suppressed.

[9] (Subsequently, though, Kang, due to the false accusations of the chancellor Lu Yan and the imperial scholar Wei Baoheng (the husband of Emperor Yizong's favorite daughter Princess Tongchang), was exiled.

Dali's emperor Qiulong thus launched a major attack on Dingbian, and neither Li nor his successor Dou Pang (竇滂) was able to repel it.

The Emperor and Consort Guo [(Princess Tongchang's mother and Emperor Yizong's favorite concubine)] missed their daughter greatly, and they commissioned the musician Li Keji [(李可及)] to author a music piece entitled, "Lamentation for a Hundred Years," with sad and delicate tones and several hundred dancers set to dance to it.

The palace storage provided large numbers of jewels to decorate the dancers, and some 800 pi [(匹, a unit of textile length)] of silk serving as the carpet they danced on.

Liu and Han had an edict issued in Emperor Yizong's name creating Li Yan crown prince.