刘歆
According to the traditional chronology based upon calculations by Liu Xin, the Xia ruled between 2205 and 1766 BC; according to the chronology based upon the "Bamboo Annals", it ruled between 1989 and 1558 BC. The Xia–Shang–Zhou Chronology Project, commissioned by the Chinese government in 1996, concluded that the Xia existed between 2070 and 1600 BC.