He proclaimed himself khagan after coup against Yujiulü Anagui by Qilifa Shifa (俟力发示发).
Emperor Xiaoming sheltered him and ordered his advisors to bring him to palace, using the opportunity.
The Chinese court sent an ambassador who was to find out Poluomen’s intentions and urge him to accept Anagui as his vassal.
Khagan was forced to transfer the capital to Liangzhou (Central Gansu) and asked to accept Wei overlordship.
Northern Wei solved the problem by partitioning Rouran between Poluomen and Anagui.