In 195 BC, after the death of Han Gaozu Liu Bang, his seventeen-year-old crown prince Liu Ying ascended the throne, becoming Emperor Hui of Han. The young emperor lacked governing experience and was gentle in nature, often indecisive in his actions, so all state power fell into the hands of Empress Lü.
After Empress Dowager Lü seized power, her first priority was to eliminate anyone who might threaten her or Emperor Hui of Han. Emperor Gaozu, Liu Bang, had greatly favored Consort Qi during his lifetime, and she bore him a son named Ruyi, who was enfeoffed as the Prince of Zhao. Consort Qi repeatedly begged Liu Bang to make Prince Ruyi the crown prince, and Liu Bang, deeply fond of this son, devised many plans to depose Liu Ying, but each time he was dissuaded by his ministers and Empress Dowager Lü. Eventually, Empress Dowager Lü brought in the "Four Whiteheads of Mount Shang" to serve as the crown prince's companions, which finally put an end to Liu Bang's thoughts of replacing the heir. Empress Dowager Lü harbored a deep hatred for Consort Qi and Ruyi, but as long as Gaozu was alive, he protected them at every turn, leaving her no opportunity to strike. Now that Gaozu had passed away, Consort Qi and Ruyi were like fish on a chopping block, at constant risk of losing their lives.
Empress Lü first cut off Consort Qi's hands and feet, forced her to drink poison to make her permanently mute, then blinded her with smoke and threw her into a latrine, turning the poor consort into a "human pig." Emperor Hui, unaware of Consort Qi's tragic fate, only knew that his mother wanted to kill Prince Ruyi of Zhao, so he brought Ruyi to live with him in the palace, never leaving his side. Empress Lü made several attempts but failed. Later, when Emperor Hui went hunting and Ruyi was sleeping in the palace, Empress Lü quickly sent someone to poison Ruyi. Upon returning and finding the Prince of Zhao dead, Emperor Hui wept bitterly in grief. Empress Lü, angered by his weakness, scolded him for being soft-hearted and took him to the latrine to see Consort Qi. Horrified by the gruesome sight, Emperor Hui trembled and cried out that his mother was too cruel, saying such brutality was not the act of a human being. After this, he fell into a deep depression and sent a message to Empress Lü: "I am not as capable as my father or my mother; I cannot manage the affairs of the realm. Let the state be handled by you." From then on, Emperor Hui spent his days in the palace indulging in drink and pleasure, while all real power fell into the hands of Empress Lü.
In August 188 BCE, Emperor Hui of Han, Liu Ying, died of melancholy. Since the emperor and his empress had no children, Empress Dowager Lü, in order to stabilize the court and reassure the ministers, had the emperor's empress pretend to be pregnant. When the time was right, she brought an infant from elsewhere and claimed it was Emperor Hui's son. To prevent the child's mother from later exposing the truth, she had her killed. She then named the child Liu Gong and installed him as emperor, known as the Former Young Emperor. From then on, Empress Dowager Lü openly presided over the court as regent, becoming the first empress in Chinese historical records to rule from behind the throne.
As the young Emperor Liu Gong gradually grew up, he inadvertently learned that his biological mother was someone else and had been killed by the Empress Dowager. In his youthful impulsiveness, the emperor angrily declared that one day he would kill Empress Lü to avenge his mother. What the young emperor did not realize was that all his attendants were spies for the Empress Dowager; shortly after he made his vengeful statement, Lü found out. To eliminate any future threat, the Empress Dowager cruelly murdered the young emperor and then found a child named Liu Hong to install as emperor, known as the Later Young Emperor. State power remained firmly in Lü's hands, and she acted even more recklessly according to her own will, with everyone fearing her.
Empress Lü was ruthless and venomous in her actions, but also intelligent and decisive, possessing the demeanor of a stateswoman. Once, after learning that Emperor Gaozu of Han had passed away, Modu Chanyu of the Xiongnu sent a letter to Empress Lü, saying: "Now you are alone, and I am alone—why don't we come together and make up for each other's solitude, achieving mutual benefit and perfection? That would be the best possible outcome." Upon reading this, Empress Lü flew into a rage and, in a fit of impulse, wanted to dispatch troops to attack the Xiongnu, but Ji Bu stepped in to dissuade her. Ji Bu suggested that Empress Lü write a letter back to Modu Chanyu, saying: "I am advanced in years and no longer as beautiful as before; most of my hair and teeth have fallen out, and I can barely walk, unfit for a long journey." Empress Lü also sent many horses and daily necessities to Modu Chanyu. Upon receiving this, Modu Chanyu realized his mistake, could not help but admire Empress Lü's wisdom and intelligence, and even dispatched envoys to the Han court to offer apologies.
When Empress Dowager Lü was in power, in order to strengthen her own rule, she first relied on her trusted advisor Shen Yiji, drawing in others to serve her, then systematically eliminated those who held opposing political views and the feudal princes enfeoffed by the late emperor, seizing their lands. She also cruelly killed two of Emperor Gaozu's sons, Prince Liu You of Zhao and Prince Liu Hui of Liang. Empress Dowager Lü was determined to enfeoff members of her own Lü family, but feared opposition from the ministers, as Emperor Gaozu had made a pact with them on a white horse before his death, vowing to support only Liu descendants and stipulating that no one without merit could be made a prince. After much deliberation, she decided to first test the ministers' opinions and raised her proposal at court. Right Chancellor Wang Ling firmly opposed this, arguing that Emperor Gaozu had decreed that only members of the Liu family could be enfeoffed as princes. These words naturally displeased Empress Dowager Lü, and seeing her anger, Wang Ling could only sigh and shake his head. Subsequently, Empress Dowager Lü removed Wang Ling from his position as Right Chancellor. Unable to bear this humiliation, Wang Ling claimed severe illness prevented him from assisting the emperor and retired to his hometown. Empress Dowager Lü was pleased with this outcome, appointing Shen Yiji as Left Chancellor and placing many key court positions in the hands of her own people. Chen Ping and Zhou Bo watched with growing concern, disapproving of Empress Dowager Lü's actions but lacking any means to counter them. Left Chancellor Shen Yiji never handled the affairs within his chancellor's authority, instead assisting Empress Dowager Lü in managing palace matters, effectively serving in the role of Palace Attendant. No matter the issue, large or small, Empress Dowager Lü would consult with Shen Yiji before making decisions, and other ministers' official matters also required Shen Yiji's review before any decisions could be made. Gradually, the Liu descendants and ministers grew increasingly dissatisfied with Empress Dowager Lü's actions and more resentful of Shen Yiji.
In 187 BC, Empress Dowager Lü began extensively enfeoffing members of the Lü clan. With Wang Ling no longer able to obstruct her, other court officials dared not speak out. She first posthumously enfeoffed her two deceased elder brothers: the eldest as King Daowu and the second as King Zhaozhao of Zhao. She enfeoffed her nephew Lü Tai as King of Lü, Lü Chan as King of Liang, Lü Lu as King of Zhao, and her grandnephew Lü Tong as King of Yan. She posthumously enfeoffed her father Lü Wen as King Xuan of Lü, and enfeoffed Zhang Yan, the son of her daughter Princess Luyuan, as King of Lu. Beyond promoting Lü family members, Empress Dowager Lü also demanded intermarriage between the Liu and Lü clans. She married Lü Lu's daughter to Liu Zhang, enfeoffing him as Marquis of Zhuxu; enfeoffed Lü Shi's son Lü Zhong as Marquis of Pei; and enfeoffed her nephew Lü Pingfu as Marquis of Liu. In 186 BC, Lü Tai, the King of Lü, died, and she enfeoffed his son Lü Jia as King of Lü. In 184 BC, Empress Dowager Lü enfeoffed her younger sister Lü Xu as Marquess of Linhuang. Roughly counting, more than a dozen members of the Lü clan were enfeoffed by Empress Dowager Lü, and in a short time, the imperial court became the domain of the Lü family.
In 180 BC, Empress Dowager Lü Zhi fell gravely ill. Fearing that after her death, the Liu family descendants and court officials would exterminate the Lü clan, she appointed her nephews, Zhao King Lü Lu and Lü King Lü Chan, as grand generals, placing them in charge of the southern and northern armies respectively. Lü repeatedly instructed them: "After I die, you must closely monitor the actions of the Liu descendants and officials, guarding against any possible rebellion. Emperor Gaozu once made them swear a solemn oath that no one outside the Liu family could be made king. Now that I have broken that oath, they surely hate me deeply. When I am laid to rest, you two must remember to stay within the imperial palace, gather all the troops, and not give them any opportunity to strike."
On August 1, 180 BC, Lü Zhi died and was buried together with Emperor Gaozu of Han, Liu Bang, in Changling.
Before her death, Empress Lü issued an edict granting gold rewards to officials according to rank, with each feudal prince receiving a thousand jin of gold, and declaring a general amnesty for the empire. The edict also appointed Lü Chan, the Prince of Lü, as Chancellor and made Lü Lu's daughter the empress. During her reign, Empress Lü cultivated a vast Lü clan faction while suppressing and attacking members of the Liu royal family, which created enormous internal conflicts within the Han ruling class. The Liu family, long harboring resentment, quickly began eliminating the Lü clan after Empress Lü's death, resulting in countless Lü family members being killed. Previously silent officials who dared not speak out also defected to the Liu side. Although the Lü clan held significant power, the Liu family's rebellion was justified, and with the Lü clan isolated and without support, they were swiftly and utterly defeated.
Prince Liu Xiang of Qi was the first to launch a rebellion. He led several princes surnamed Liu, joining forces with Chen Ping and Zhou Bo to suppress the Lü clan. After a fierce struggle, the Liu family ultimately emerged victorious, and the Lü family was nearly wiped out. This was an outcome that Empress Lü could never have imagined in her lifetime.
After Emperor Gaozu of Han passed away, Empress Lü held power for fifteen years. Although she did many selfish things, she also accomplished much good for the common people. She advocated for simplified laws and reduced prohibitions, allowing the populace to rest and recover; she granted tax reductions to hardworking and outstanding farmers; she lowered tax rates; she encouraged people who had fled into the mountains due to war to return home, and ordered officials to treat them well by allocating land and houses; she periodically released government slaves and sent them back to farm; she abolished some of the harsh laws of the Qin Dynasty; and she adopted a policy of peace through marriage with the Xiongnu to spare the people the suffering caused by war.
These policies effectively improved social productivity and the living standards of the common people, alleviated conflicts between the Han Dynasty and foreign tribes, accumulated considerable wealth for the Han court, and strengthened the nation's overall power.