Liu Bang, who is known in history as Gaozu (Kao-tsu), meaning "high progenitor", died of an arrow wound in battle. His eldest son by Empress Lu became the new ruler Huidi (Hui-ti). Huidi reigned as an adult even though he was only 15 years old.
He was noted for his filial piety and respect for learning. He ordered the lifting of a ban on books that the previous Qin (Ch’in) dynasty had enacted. However, his strong-willed mother, who vindictively killed one of her husband’s concubines and several of her stepsons, dominated Huidi.
Her actions so terrified him that he became bedridden for a year and never dared to challenge his mother again. Huidi died in 188 b.c.e., leaving a young son. That son, and another whom Empress Lu adopted as her grandson, became puppet emperors with the empress as regent.
Empress Lu followed her husband’s policy of government, which included peace with the powerful Xiongnu nomads. In 192 b.c.e. she received this letter from Maotun, the Xiongnu ruler, which read: "I am a lonely widowed ruler, born amidst the marshes and brought up on the wild steppes in the land of cattle and horses ... Your Majesty is also a widowed ruler living in a life of solitude. Both of us are without pleasures and lack any way to amuse ourselves. It is my hope that we can exchange that which we have for that which we are lacking".
This was a marriage proposal to join their two empires. Although the empress was furious, China was too weak for war, and she had to reply humbly thus: "My age is advanced and my vitality is weakening. Both my hair and teeth are falling out, and I cannot even walk steadily ... I am not worthy of his [Maotun’s] lowering himself. But my country has done nothing wrong, and I hope he [Maotun] will spare it". She did, however, send a Han princess to be his wife.
Empress Lu refrained from formally proclaiming herself as reigning empress, but many of her actions seemed preparation for the enthronement of a man from the Lu family as emperor.
She appointed a brother as chancellor and another as commander in chief and elevated several members of her family to the titles of kings and marquises, granting them large fiefs. Encouraged by her policy, members of her family attempted to seize power when she died in 180 b.c.e., but surviving members of the Liu clan and Han loyalists thwarted them.
A son of Gaozu led a march on the capital city Chang’an (Ch’ang-an), captured the city, and wiped out the Lu clan. Empress Lu set a precedent for most of the Han era: strong mothers and grandmothers of young rulers seizing power and elevating their families.
Some rulers would be murdered when they grew up and attempted to regain power, others were intimidated to acquiesce. One, the long-lived Empress Wang allowed her brothers to share power, and eventually allowed her nephew Wang Mang to usurp the throne in 9 c.e.