Shin Chaeho
Historical Korean claims of Manchuria can be traced back to the late Joseon dynasty. It was common in late Joseon dynasty to write about "old lands of Goguryeo", an expression of nostalgia for the north. In the early 20th century, Korean nationalist historians like Shin Chaeho, advocated a complete unification of Korean peninsula and Manchuria in order to restore the "ancient lands of Dangun".