Map according to Tan Qixiang 谭其骧 (1987), Zhongguo lishi ditu ji 中国历史地图集. Cao was located in the Yellow River Plain and was conquered by its neighbour, Song. Click to enlarge.
The first ruler of Cao was Cao Shu Zhenduo 曹叔振鐸, a brother of King Wu of Zhou 周武王. Earl You 曹幽伯 (r. 834-826) was killed by his younger brother, Earl Dai 曹戴伯 (r. 825-796). During the reign of Duke Gong 曹共公 (r. 652-618), Prince Chong'er 重耳 of Jin 晉 stayed in Cao and was not treated with the necessary respect. When he became duke of Jin (Duke Wen 晉文公, r. 636-628), he took revenge and attacked Cao. Duke Gong of Cao was captured and only released after a while.
Duke Cheng 曹成公 (r. 577-555) met the same fate and was taken prisoner by Jin for a while. Duke Dao 曹悼公 (r. 523-515) was taken prisoner by the state of Song 宋. When he was absent, his brother, Prince Ye 野, was enthroned as Duke Sheng 曹聲公 (r. 515-512). Duke Gong died in Song, but his corpse was transferred to Cao to be buried. Duke Sheng was assassinated by his uncle, who mounted the throne as Duke Yin 曹隱公 (r. 511-506). Duke Yin himself was killed by a brother of Duke Sheng, Duke Jing 曹靖公 (r. 505-502). These fratricidal phase was ended with Duke Jing's son, Prince Yang 陽, who was also the last ruler of Cao, known as Earl Yang 曹伯陽 (r. 501-487).
The history of Cao ends with a dream, in which only a certain Gongsun Qiang 公孫彊 would be able to save the state. Gongsun Qiang was a hunter, and because of the dream, he stood in high favour of Earl Yang. He suggested to the duke to become a hegemonial lord (ba 霸), and in the belief to be on the safer side, the Earl offended the ruler of Song and ignored to pay reverence to Jin. When the army of Song attacked, the duke of Jin refused to help Cao. The Earl and Gongsun Qiang were executed, and the dynasty was ended. Cao became part of Song.
|Capital: Taoqiu 陶丘 (modern Dingtao 定陶, Shandong)|
|dynastic title||personal name||time|
|Cao Shu Zhenduo 曹叔振鐸||Ji Zhenyi 姬振鐸, brother of King Wu of Zhou 周武王|
|Cao Taibo 曹太伯||Ji Pi 姬脾|
|Cao Zhongjun 曹仲君||Ji Ping 姬平|
|Cao Gongbo 曹宮伯||Ji Hou 姬侯|
|Cao Xiaobo 曹孝伯||Ji Yun 姬雲|
|Cao Yibo 曹夷伯||Ji Xi 姬喜||865-835|
|Cao Youbo 曹幽伯||Ji Qiang 姬疆||835-826|
|Cao Daibo 曹戴伯||Ji Su 姬蘇||826-796|
|Cao Huibo 曹惠伯||Ji Zhi 姬雉||796-760|
|Cao Mugong 曹穆公||Ji Wu 姬武||760-757|
|Cao Huangong 曹桓公||Ji Zhongsheng 姬終生||757-702|
|Cao Zhuanggong 曹莊公||Ji Shegu 姬射姑||702-671|
|Cao Xigong 曹釐公 or 僖公||Ji Ji 姬羈||671-661|
|Cao Zhaogong 曹昭公||Ji Ban 姬班||661-653|
|Cao Gonggong 曹共公||Ji Xiang 姬襄||653-618|
|Cao Wengong 曹文公||Ji Shou 姬壽||618-595|
|Cao Xuangong 曹宣公||Ji Jiang 姬彊||595-578|
|Cao Chenggong 曹成公||Ji Fuchu 姬負芻||578-555|
|Cao Wugong 曹武公||Ji Sheng 姬勝||555-528|
|Cao Pinggong 曹平公||Ji Xu 姬須||528-524|
|Cao Daogong 曹悼公||Ji Wu 姬午||524-515|
|Cao Xianggong 曹襄公 or Shenggong 聲公||Ji Ye 姬野||515-512|
|Cao Yinggong 曹隱公||Ji Tong 姬通||512-506|
|Cao Jinggong 曹靖公||Ji Lu 姬露||506-502|
|Yang, Baron of Cao 曹伯陽||Ji Yang 姬陽||502-487|
|487 Cao conquered by Song 宋.|