Cao, Chinese empress dowager
Empress Dowager Cao (曹太后, personal name unknown) (died August 3, 925 ), formally, Empress Zhenjian (貞簡皇后, "virtuous and humble"), was a concubine to the late Tang dynasty warlord Li Keyong and the mother of his son, Li Cunxu, who later established the Later Tang dynasty as its Emperor Zhuangzong. After the establishment of Later Tang, she was honored as empress dowager.