举足轻重 — “To play a decisive role”

The idiom "举足轻重" (jǔ zú qīng zhòng) originates from the Eastern Han Dynasty, involving General Dou Rong. Towards the end of the Xin Dynasty, Dou Rong served as a general and later surrendered to Liu Xuan, becoming the commandant of Zhangye's dependency.

After Liu Xuan's defeat, Dou Rong allied with five prefectures, including Jiuquan and Dunhuang, establishing a powerful regional government in Hexi (west of the Yellow River), known as the Grand General of the Five Hexi Prefectures.

When Emperor Guangwu Liu Xiu established his rule and stabilized the central plains, Dou Rong considered pledging allegiance to Liu Xiu. He sent his chief clerk, Liu Jun, with precious treasures to meet Liu Xiu. Liu Xiu gladly accepted his allegiance and appointed Dou Rong as the Governor of Liangzhou, bestowing upon him two hundred catties of gold.

Liu Xiu also wrote a letter to Dou Rong, analyzing the political and military situation of the time and commending Dou Rong's governance of the five Hexi prefectures. In the letter, Liu Xiu pointed out that, besides the imperial court and Dou Rong, there were also Gongsun Shu in Yizhou and Wei Xiao in Tianshui, both ambitious and aspiring to become kings. In this critical situation, Dou Rong's position was "举足轻重" (of pivotal importance), playing a crucial role in unifying the entire nation.

Upon receiving Emperor Guangwu's letter, Dou Rong expressed his undivided loyalty to the imperial court. Later, he led his troops to assist the court in suppressing Wei Xiao's rebellion and eventually defeated Gongsun Shu. Consequently, Liu Xiu enfeoffed him as Marquis of Anfeng and appointed him Grand Minister of Works (大司空).