Wiman’s coupd'état and Establishment of Wiman Joseon

There have been many debates about the ancestry of Wiman, but it is natural to understand it as belonging to Joseon, from the fact that the surname which had not been known in those days was attached to it in the next generation and that his tribe is grasped as figures who had Joseon’s customs. Wiman already strengthened his power by gathering 燕(Yan) people who were scattered at the end of the Age of the Warring states and is presumed to maintain his tribe’s identity by supporting Gunhyeon-system, and therefore achieving the recognition of its independence in the Qin dynasty. A new record suggesting that Wiman defected to Joseon around 209 B.C when Jiseung raised an army appears in『Huhanseo(後漢書)』. It is, however, natural to understand that Wiman defected to Joseon at the early Jinhan, based on『Sagi(史記)』and『Wiryak(魏略)』, which more specifically record the defection. Wiman already had competence and experience as an independent powerful man in the Liaodong area, since the end of the Age of the Warring states. Wiman could secure his military power for staging a coup for a short period, as tens of thousands of immigrants from the mainlands already resided in the western edge of Old Joseon. Wiman cound succeed in the coup by quickly capturing Wanggeom Castle. The defense system of Old Joseon was vulnerable to the internal coup, which can be understand as the biggest cause of its collapse.