Liu Bang had many talented and capable individuals under his command, and Xiao He was one of them. He supported Liu Bang's uprising in Pei County, stayed by Liu Bang's side throughout, and repeatedly offered strategic advice. It can be said that Liu Bang's great achievements were inseparable from Xiao He's numerous contributions. When Liu Bang captured Xianyang, while others were captivated by the rooms full of gold, silver, jewels, and beautiful women, Xiao He alone hurried to the mansions of the Qin Dynasty's Prime Minister and Censor-in-Chief, collecting all the household registries, maps, legal documents, and other records of the Qin Dynasty, forbidding anyone from trampling on them or entering the Prime Minister's and Censor-in-Chief's residences. He selected a few quick and reliable people to organize these precious materials and stored them all properly. Some might ask, what was the use of keeping these? Couldn't Liu Bang just conduct a large-scale census after establishing his state? But upon careful thought, things were not that simple—why abandon ready-made resources and go through great trouble instead? According to Qin Dynasty regulations, the Prime Minister assisted the emperor in managing state affairs, while the Censor-in-Chief oversaw all officials. The documents these two officials held essentially represented the entire national situation; aside from the military, the Prime Minister and Censor-in-Chief controlled nearly all government affairs. Having previously served in the county office, Xiao He naturally understood this, so after capturing Xianyang, his first thought was to seize these documents concerning national conditions for future use.
As for Liu Bang, who would later become the founding emperor of the Han Dynasty, after entering Xianyang, he refused to leave the splendid Qin palace, and had it not been for the advice of Fan Kuai and Zhang Liang, he might have ended up like Qin Ershi, Hu Hai. When Liu Bang saw that Xiao He had collected all the documents and files from the Qin Dynasty, he felt deeply ashamed, admitted that he was no match for him, and praised Xiao He as a rare talent. Thanks to Xiao He's records, Liu Bang gained a detailed understanding of the population, culture, geography, and other aspects of the entire country at that time, which laid the foundation for the establishment of the Han Dynasty.
After the establishment of the Han Dynasty, Xiao He, building on Liu Bang's "Three Chapters of the Covenant," consulted the laws of the Qin Dynasty and added some statutes that suited the social conditions of the time. Through his adjustments, the legal code was divided into nine sections, known as the "Nine Chapters of Han Law." Compared to the harsh and cruel laws of the Qin Dynasty, the Han laws appeared more humane. After Emperor Gaozu Liu Bang passed away, Emperor Hui of Han, Liu Ying, continued to appoint Xiao He as Chancellor. By then, Xiao He was already very old, but he still tirelessly managed state affairs without interruption.
In 193 BC, Xiao He fell ill from years of overwork, and Emperor Hui of Han personally visited him, taking the opportunity to ask a question weighing on his mind: "If you, Chancellor, should pass away, who would be suitable to take your place?" Xiao He did not answer immediately but instead asked Emperor Hui if he had any candidates in mind. Emperor Hui hesitated and asked, "What do you think of Cao Can?" Upon hearing this, Xiao He, despite his frail condition, struggled to rise and kowtow to the emperor, repeatedly saying, "If Your Majesty appoints Cao Can as Chancellor, the Han Dynasty will surely flourish forever." Shortly after this, Xiao He passed away.
Xiao He and Cao Can were once very close friends, but due to some disagreements, they gradually drifted apart. Xiao He always believed that only Cao Can could succeed him, and Cao Can understood this as well, so after Xiao He's death, Cao Can instructed his family to pack their belongings, saying he would soon be going to the court to serve as chancellor. A few days later, Emperor Hui of Han's envoy arrived at Cao Can's home and announced that he would take over the position of chancellor.
After Cao Can succeeded as Prime Minister, he made no changes to the nation's laws or policies, executing all affairs according to established systems, allowing the people to live in peace and contentment while officials diligently fulfilled their duties. Only when selecting officials did Cao Can put in great effort, personally screening candidates and specifically choosing those who were taciturn, upright, and loyal for important positions, while those who were glib-tongued were harshly rebuked and driven away by him.
The ministers, seeing that Cao Can always neglected state affairs, were both puzzled and confused, so they visited him one after another to urge him to initiate at least one or two reforms. However, Cao Can turned a deaf ear to their words; whenever a minister arrived, he would bring out rich and mellow fine wine to entertain them, drinking cup after cup and preventing them from speaking. Once the ministers were drunk, the words they wanted to say naturally could not be uttered.
The Chancellor's residence was located very close to the homes of other ministers, and sounds of drinking and finger-guessing games could often be heard from next door; the staff at the Chancellor's mansion deeply detested such behavior, but they dared not voice their anger because Cao Can had once ordered that anyone caught privately gossiping about officials would be severely punished. Cao Can never made a big deal out of others' minor mistakes, and under his governance, there were far fewer disputes among officials at court.
Emperor Hui of Han, like many of his ministers, was puzzled by Cao Can's apparent inaction. The emperor suspected that Cao Can looked down on him for being young and unwilling to support him. Cao Can's son, Cao Zhu, served as a court official, so Emperor Hui took the opportunity when Cao Zhu was on leave to ask him to inquire why his father had not taken any action. When Cao Zhu returned home and asked his father, he was beaten two hundred times with a bamboo board, nearly unable to get up. Cao Can scolded his son as he beat him, telling him to focus on assisting the emperor properly instead of gossiping. Back at court, Cao Zhu reported the beating and his father's words to Emperor Hui, who was shocked and immediately summoned Cao Can for an explanation. Upon learning of the emperor's doubts, Cao Can first removed his hat and knelt down, then asked, "Compared to the late emperor, do you consider yourself more wise?" Emperor Hui replied shamefully, "How could I compare to the late emperor? I am far inferior." Cao Can then asked, "In your view, does my ability match that of Prime Minister Xiao He?" Emperor Hui smiled and said, "You are slightly inferior." Cao Can then said seriously, "Exactly. The late emperor was wiser than you, and Prime Minister Xiao was more capable than me. They established a series of laws and policies at the beginning of the dynasty, sufficient to ensure the lives and production of the people and society. Since they covered everything comprehensively, could we possibly make more remarkable moves than they did? The late emperor conquered the realm and stabilized the foundation of the state. Now, our task is to preserve this realm, not to think about how to redesign it, because our predecessors have already planned it for us. We only need to implement the policies they set forth; otherwise, society would fall into chaos. In that case, do you still think I have done wrong?"
Emperor Hui of Han suddenly realized the truth and could not help but greatly praise Cao Can. Later generations used the phrase "Xiao's rules followed by Cao" to describe handling affairs according to the experience of predecessors. Cao Can served as prime minister for three years, managing the state according to the laws and regulations established by Xiao He, and the people all applauded in praise. The politics and economy of the Western Han Dynasty achieved tremendous development, and the people's living standards improved day by day.