The Cause of Implementing Brothers Succession to the Throne in Shang Dynasty under the Background of Xia Dynasty

Regularly,according to history records the system of Xia dynasty's accession to the throne is Father-Son inheritance,and it is the same on its tribal leaders in pre-Shang times.But after Shang replaced Xia dynasty to rule over the world,it was changed.The system of accession to the throne became Brothers succession.The cause perhaps lied in Xia dynasty's being as the first central family kindom and the complicated situation Shang Tang confronted after his exterminating Xia dynasty.So it is written for searching after the concrete causes of this change and Shang Tang's countermeasures:Brothers succession and polygyny.