See other feudal states of the Zhou period. Cao 曹 was a rather unimportant mid-sized feudal state of the Zhou period 周 (11th cent.-221 BCE) with an unspectacular history (at least as far as historiography informs us). 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. Source: Shiji 史記 35, Guan Cai [Cao] shijia 管蔡世家. Rulers of Cao 曹 Capital: Taoqiu 陶丘 (modern Dingtao 定陶, Shandong) Note: The reign dates are given according to Western reckoning. In Chinese chronicles, the year after the first New Year of a rule is seen as the first year of reign. Example: Duke Zhao died in 653, his son Duke Gong immediately acceeded to the throne, yet Chinese chronicles see 652 as his first (full) year of reign (Cao Gongong 1). dynastic title See also titles of rulers. 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.