In the late Western Han Dynasty, the imperial relative Wang Mang usurped the throne and changed the dynasty's name to "Xin." Because Wang Mang enforced even harsher policies than the Western Han, peasant uprisings like the Green Woodsmen and Red Eyebrows erupted. Liu Xuan, a distant imperial clansman, joined the Green Woodsmen. To expand their influence, they supported him as the Gengshi Emperor and restored the Han dynasty's name.
After Liu Xuan became emperor, he spent his days and nights drinking and reveling with his concubines and palace maids in the inner court, often getting thoroughly drunk and neglecting state affairs. When ministers had matters to discuss, he refused to meet them in person, instead ordering attendants to relay words through a curtain, which stirred resentment among his generals.
Liu Xuan married the daughter of Right Grand Sima Zhao Meng and made her his consort, doting on her so much that he handed all state affairs over to Zhao Meng. Zhao Meng, relying on his power, acted arbitrarily and autocratically. When someone reported this to Liu Xuan, Liu Xuan had the reporter executed. A close attendant of Liu Xuan offended Zhao Meng, and Zhao Meng wanted to kill him. Liu Xuan pleaded for the attendant's life, but Zhao Meng ignored him and killed the man anyway.
At that time, Wang Mang's regime had not yet been overthrown, and various warlords were seizing territory with their armies. Some ministers and generals under Liu Xuan formed factions and cultivated personal loyalties, granting official positions and imperial gifts based on favoritism and personal grudges. Even petty rogues, merchants, and cooks were given titles and honors. In the capital city of Chang'an, a popular rhyme mocked this chaos: "The kitchen cook becomes a General of the Palace; the rotten sheep stomach becomes a Cavalry Commandant; the rotten sheep head becomes a Marquis within the Passes."
Advisor Li Shu urged Emperor Liu Xuan to prepare for danger in times of safety, reform governance, and recruit talent, but Liu Xuan ignored the advice and imprisoned Li Shu. Soon, the Red Eyebrows army installed another distant imperial relative, Liu Penzi, as emperor, stormed Chang'an, and executed Liu Xuan.
Later, the idiom "Rotten Sheep's Head" came to be used as a metaphor for indiscriminately granting official titles.
Source: *Book of the Later Han*, Chapter "Biography of Liu Xuan"
Meaning of the Idiom: Later, the Chinese idiom "烂羊头" came to describe indiscriminately granting official titles.