Since the late 19th century, modernization and imperialization have progressed simultaneously in Japan. Considering this historical process of Japan, the studies of Japanese historians at that time has the attributes of modern historiography as well as justifying Japan’s invasion into the surrounding areas. It is also said that the establishment and development of modern historiography in Japan was the process of forming the “Tōyō.”(the Orient, 東洋) Then, Japanese historians’ studies on the history of East Asia, including Korean history at the time, needs to be positioned in the process of forming “Tōyō,” and its meaning should be considered.
On the other hand, superficially, Goryeo dynasty was a time to show the external and internal turmoil of Korean history to Japanese historians. This is because during the Goryeo Dynasty, there were well known events represented by repeated invasions by the northern people such like Khitans, Jurchens, Mongols and rebellion of the Myocheng, political changes by soldiers. However, if you look at past Japanese historians’ studies on the Goryeo Dynasty, you can see something interesting. It shows considerable interest in the Mongol invasion of Goryeo, interference of the Yuan, the invasion to Japan of the Goryeo and Mongol Allies, and the external relationship of Goryeo before and after the Mongol Invasion to Japan.
This is based primarily on the theory of heteronomy on Korean history, given that it focuses on external relations during the Goryeo Dynasty. However, “Mongol Invasion to Japan” is directly related to Japanese history, and it was an event that could maximize the status of Japanese history in that Yuan, the world’s strongest country at the time, did not achieve its goal. In addition, the incident was literally an East Asian incident involving several countries at the time, including Goryeo, Yuan, Sung and Japan.
This paper considers the studies of Japanese historians in the past who approached the Mongol Invasion to Japan through external relations of Goryeo in terms of the formation of the so-called “Tōyō.” At that time, Japanese historians understood that the establishment of suzerainty of Yuan in Goryeo was a prerequisite for Yuan’s policy toward Japan. In other words, it looked at the external relationship of Goryeo as a precondition for understanding the relationship between the continent(Yuan) and Japan. In addition, as a precondition for understanding Mongol invasion to Japan, Yuan’s conquer on South Sung as well as its relationship with Goryeo and Japan was included in the field of view, positioning Japan’s existence as an important variable of East Asian international politics. Japanese historians at the time expanded their perspective to the past before the mid-13th century from this perspective. Since the founding of the Goryeo Dynasty, they have studied by considering the relationship and transportation of the three East Asian countries, Goryeo, Sung and Japan. And through this, they insisted the continuous relations between continent and Japan. In other words, Japanese historians who focused on the external relationship of Goryeo for understanding the Mongol invasion to Japan, looked at the incident as an East Asian event and connected the continent with Japan, but also positioned Japan as a major variable in the historical process of the continent.