Empress Lü Zhi
When Emperor Hui died in autumn 188 BCE, his son (noting that this parentage is disputed) ascended to the throne as Emperor Qianshao. However, there was no pretension that he was actually in charge; Emperor Hui's mother Empress Lü Zhi, titled "Empress Dowager Lü" (never "Grand Empress Dowager" despite that she was grandmother of the emperor), was the one who publicly and actually controlled the political power.