During the Eastern Han Dynasty, Dou Rong's family had served as officials in Hexi for generations. At the end of Wang Mang's reign, he became "General of the Waves." Later, after the defeat at the Battle of Kunyang, he surrendered to the rebel leader Liu Xuan and became the Governor of Julu.
After Liu Xuan's defeat, he allied with five commanderies including Jiuquan and Dunhuang to establish an independent regime in Hexi, and was elected by common acclaim as the Grand General of the Five Commanderies of Hexi.
The Hexi region was already known for its simple folk customs, and when Dou Rong implemented lenient policies, the land flourished with abundant grain and strong soldiers, drawing refugees from nearby areas to seek his protection.
After Emperor Guangwu of Han, Liu Xiu, seized power, Dou Rong intended to pledge allegiance. He sent his chief secretary, Liu Jun, to present a memorial and offer horses as a gesture of sincerity.
Emperor Liu Xiu was overjoyed when Dou Rong, who held firm control over the Hexi region, expressed willingness to submit. He appointed Dou Rong as Governor of Liangzhou and issued an imperial decree praising his governance of the five commanderies west of the Yellow River. Liu Xiu declared, "Now Long and Shu are at war, and your every move carries weight... The land may be divided, but the people cannot be split—each must adapt to their own circumstances."
Emperor Guangwu of Han issued an edict affirming Dou Rong's crucial position, and from then on, Dou Rong remained wholeheartedly loyal to the emperor. When Wei Xiao later rebelled against the court, Dou Rong raised a massive army, coordinating with Han forces from east and west to crush Wei Xiao's rebellion decisively.
Emperor Guangwu of the Eastern Han Dynasty gained the support of Dou Rong, greatly strengthening his forces. He first eliminated Gongsun Shu, who had declared himself emperor in Yizhou, then swiftly pacified Longxi and defeated Wei Xiao, unifying China.
Later, people used the idiom "A Foot's Weight Tips the Scale" to describe actions that greatly influence the overall situation, or a position of critical importance.
Source: *Book of the Later Han*, "Biography of Dou Rong"
Meaning of the Idiom: Later, the Chinese idiom "举足轻重" came to describe actions that greatly influence the overall situation, or a position of critical importance.