After more than 30 years of diplomatic mediation and military conquests, Hammurabi, king of the Old Babylon Kingdom, re-established a united kingship in the Mesopotamia in 1755 BC, ending more than 200 years of political division in that region. The diversity of cultural traditions, laws and customs, the complexity of religious beliefs, and problems of the identity of citizens, poses a great challenge to the governance of this new country. Unearthed documents such as Hammurabi's Codes, inscriptions and letters show that he carried on the old tradition of governance in the Mesopotamia, claiming the legitimacy of his rule with the idea of "the divine right of Kings" and that he is guided by the spirit of rule by law, which aimed at establishing social fairness and justice, established and consolidated the class order and family ethical order of Babylonian society, protected people's right to property and safety of life by laws. The ideas and measures of Hanmurabi governing the country by law provide an important reference for the study of the governance ideas and traditions of the Mesopotamia.