Empress Lü Gao-Hou
When Liu Bang became Emperor, his wife became Empress Lü or Gou-Hou . After Liu Bang's death in 195 BC, the now Empress Dowager took over the rule of the Empire, which resulted in a power struggle within the families.
Empress Lü removed members from her late husband's family from positions of power, and replaced them with members of her own family.
At first, Empress Lü used Liu Ying as a puppet Emperor. He was weak of body and mind and easy to manipulate. When Liu Ying died the Empress used Liu Gong as puppet to prolong her rule.
After five years of rule over Liu Gong, the Empress died, and Liu Bangs deposed relatives moved to take back their family's dominance. In the process, all members of the late Empress' family were killed.