Deconstructing the Official History of Koryŏ in Late Chosŏn: The Discovery of the Un’gok sisa and the Refutation of the Theory that Sin Ton Sired Kings U and Ch'ang

This article investigates how a new way of interpreting the history of the Koryŏ dynasty that differed from the state-sponsored Koryŏsa emerged in the seventeenth century by focusing on changes in how King U and King Ch’ang were treated in historiography. In the Koryŏsa, it is said that the son and grandson of King Kongmin, King U and King Ch’ang respectively, were in fact the descendants of the monk Sin Ton. As such, they were not legitimate kings and were considered usurpers to the throne and labeled traitors. This historical evaluation, in suggesting that Koryŏ’s legitimate line of succession had ended before King U and King Ch’ang, was created as a political pretext to legitimize the founding of the Chosŏn dynasty. This assessment in the Koryŏsa greatly influenced the people of Chosŏn, but it was strongly challenged in the early seventeenth century with the discovery of the Un’gok sisa, written by Wŏn Ch’ŏnsŏk. This text, representing the voice of a man of Koryŏ, recognized King U and King Ch’ang as King Kongmin’s descendants. Among those who saw these writings, there were several who concluded that the Koryŏsa’s narrative, which saw King U and Ch’ang as Sin’s descendants, was unfounded. At first, the number of people who thought this way was but few. However, by the eighteenth century, historical works that treated King U and King Ch’ang as legitimate Koryŏ kings emerged. An Chŏngbok’s Tongsa kangmok was a culmination of this trend. An Chŏngbok understood the historical past in terms of state and monarchical absolutism. An extension of this thinking was his affirmation of King U and King Ch’ang as Koryŏ kings. Afterward, by the end of the eighteenth century, historical interpretation of the Koryŏ period in Chosŏn changed from that of the Koryŏsa to that of An’s Tongsa kangmok. One can say that with the twentieth century, modern interpretations of Koryŏ history are deeply informed by the conclusions of the Tongsa kangmok.