The South Korean Yun Nae-hyŏn proposed in 1985 that Gojoseon lasted for two thousand years from before 2333 BCE, stretching from Hebei in north China to all of Korea. Important dissenters to the Liaodong-as-Korean view during Joseon included Jeong Yak-yong, who argued that Liaodong was "superfluous" to Korea's natural river borders; and Seongho Yi Ik, who regarded irredentism against China as a "greedy ambition" that could lead to trouble in the future; against the nationalist historians of 1910 who bemoaned the "loss" of Manchuria and decline of the Korean minjok, An Hwak represented a dissenting voice. The Daejonggyo cult of Dangun wrote "historical tales" (sahwa) which influenced Korean nationalist historiography of the 20th century. The pan-Dongyi pan-Northeast Asian arguments of the sahwa included the assertion that the Korean nation included "not only the Korean peninsula and Manchuria, but also northeastern China", considering the Emperors of Shun, Liao, Jin, Yuan, and Qing as part of Korean history. This expanded concept of the Korean nation was included in Kim Kyo-hŏn's Korean history textbooks intended to boost the morale of military cadets studying in exile in China. According to Kim, since all these peoples who led the dynasties originated in Manchuria—unlike, say, Jizi of Gija Joseon—, they are all descendants of Dangun, and thus part of the Korean minjok's "northern" branch of history. As a result, he considered all the lands conquered by those peoples, including most lately "the land of the Han, Mongolia, the territory of the Hui, and Tibet" all the way down to Burma as included in the territory of the Korean minjok. Yi Sang-ryong made a number of arguments in common with Shin, Kim Kyohŏn and Park Eun-sik: that the Manchu people were actually Korean; that the Four Commanderies of Han were located in Liaodong and not "Korean" territory; and that some portion of Korean history should be centered in Manchuria, with the goal of creating a greater Joseon state which included the territory. Shin argued that the "trends in geographical history" portended future Korean control over former Goguryeo territories, and advocated Korean emigration to "relight" (chunggwang) the lost history of Dangun. As a result of peasant uprisings, famines, and Imperial Japanese encouragement, Korean immigration to Manchuria soared from 1860, reaching 400,000 Koreans by 1920; 900,000 by 1931, and over two million by 1945.
