Wiman Seizes Gojoseon
Wiman, who had come from Yan with about a thousand followers, ousted King Jun and took the throne; Jun fled south and called himself King of Han.

Prof. Gary Lee Todd · CC BY-SA 4.0 · Source
Amid the fall of Qin, Wiman arrived wearing a topknot and native dress. King Jun trusted him to guard the western frontier, but Wiman built up his strength and seized Wanggeom-seong.
Because he kept the name Joseon and gave high office to locals, Wiman’s state is seen as a continuation of Gojoseon. Iron spread widely under his line, and Gojoseon grew rich as middleman between Han and the southern state of Jin.