Ming tombs
In 1615, the crown prince became infuriated with his concubine, Lady Liu, who was the mother of the future Chongzhen Emperor. He ordered her punished, during which ordeal Lady Liu died. It is debated whether the crown prince ordered her to be killed or if her death was an accident. Fearing that this incident would further turn his father against him and towards Zhu Changxun, the crown prince had Lady Liu secretly buried in the Western Hills near Beijing and forbade palace staff from mentioning the affair. On his ascension to the throne, the Chongzhen Emperor had Lady Liu reburied in the Ming tombs next to her husband.