Wu Han, courtesy name Ziyan, was a native of Nanyang who grew up in deep poverty. During the final years of Wang Mang's reign, he traded horses across the Yan and Zhao regions, befriending many bold heroes. When Emperor Gengshi Liu Xuan ascended the throne, Wu Han caught the eye of Liu Xuan's envoy, Han Hong, and was appointed magistrate of Anle County. Soon after, he defected to Liu Xiu. Because Wu Han was honest, brave, and shrewd, winning battle after battle, he gradually earned Liu Xiu's trust. After Liu Xiu became emperor, he appointed Wu Han as Grand Marshal and Marquis of Wuyang.
In the early Eastern Han Dynasty, the realm remained chaotic as self-proclaimed generals, nobles, and officials each carved out their own territories under the banner of "Han." A Han clan member named Liu Yong had declared himself emperor even before Liu Xiu. Shortly after Liu Xiu's ascension, he focused on suppressing these rival factions to secure his rule. In the second year of the Jianwu era, Wu Han led nine generals, including Grand Minister Wang Liang and General-in-Chief Zhu You, to defeat several rebel forces—Tanxiang, Ye, Nanyang, Changcheng, Tongma, and Wufan—before besieging Liu Yong's general Su Mao at Guangdong. Another of Liu Yong's generals, Zhou Jian, gathered over 100,000 men to rescue Su Mao. Wu Han clashed with him but lost the battle, fell from his horse, and injured his knee. Zhou Jian seized the opportunity to enter Guangdong and join forces with Su Mao. Back in camp, Wu Han's generals told him, "With the enemy at our doorstep and you wounded in bed, the soldiers are growing anxious." Hearing this, Wu Han roused himself, bandaged his wound, and ordered cattle and sheep slaughtered for a hearty feast. He encouraged his troops, saying, "Though the enemy is numerous, they are mere looters without honor, unwilling to die for a righteous cause—'they yield no ground in victory and offer no rescue in defeat.' Now is the time to strive for noble titles; fight with all your might!" The army's morale soared.
The next morning, Su Mao and Zhou Jian led their troops to surround Wu Han. Wu Han dispatched four elite units and 3,000 Wuhuan cavalry, advancing with drums thundering in unison to meet the enemy. Despite his own injuries, Wu Han donned his armor, raised his halberd high, and bellowed, "When you hear the drum, shout and charge forward—anyone who retreats will be beheaded!" His soldiers surged ahead, overwhelming Zhou Jian's forces, who fled back into the city. Wu Han's men pressed the attack, storming the gates, forcing Zhou Jian and Su Mao to abandon the city and escape.
Wu Han, even when the battle was unfavorable and his troops were panicked, remained calm and composed, inspiring his soldiers. Sometimes, Emperor Guangwu Liu Xiu sent someone to see what the Grand Marshal was doing, and the envoy always reported, "He is repairing weapons of war." Liu Xiu praised, "Grand Marshal Wu is barely satisfactory."
The idiom "Chai Qiang Ren Yi" originally meant to be somewhat inspiring, and later came to mean fairly satisfactory.
Source: *Book of the Later Han*, "Biography of Wu Han"
Meaning of the Idiom: Later, the Chinese idiom "差强人意" came to describe fairly satisfactory.