After Myeongnim Dap-bu assassinated Chadae, Sindae was invited to ascend the throne by court officials.
To strengthen royal power, he created the supreme ministerial post of guksang(國相), and appointed Myeongnim Dap-bu to the office.
Goguryeo united with the Xianbei and attacked the Yuju and Byeongju districts of the Later Han dynasty of China; however, their alliance brought no great victory.
[4] The Later Han invaded Goguryeo in the eleventh month of 172, but were destroyed by Myeongnim Dap-bu's army at Jwawon(坐原),[5] gaining success to expand its territory into western side of the kingdom.
[3] In 176, he named his second son Nammu as the crown prince (subsequent king Gogukcheon), which consolidated the tradition of patrilineal succession.