The History of the Name of the Sea of Japan

Discussions were held over the name of the Sea of Japan this summer, but first the historic fact of the name should be assessed rationally. In the map Kunyu Wanguo Quantu drawn up by an Italian missionary priest of the Jesuit Order Matteo Ricci 400 years ago, the "Sea of Japan" was written down in kanji already, subsequently that name was imported into and pervaded Japan from the West.

Recent state of affairs surrounding the term "Sea of Japan"

The pros and cons of the term "Sea of Japan" were widely reported in the media this past August and September. The debate started when the International Hydrographic Organization (IHO), which formulates international guidelines for nautical charts, accepted Korean allegations and proposed that the term "Sea of Japan," which has been used internationally, be scratched. The Japanese Government immediately protested to the IHO in pursuit of the withdrawal of the proposal. At the Eighth United Nations Conference on the Standardization of Geographical Names (UNCSGN), which was held around the same time, South Korea and North Korea objected to the term, but Japan refuted their claim.
In the end, the IHO's proposal was withdrawn because of criticism received from various member countries and procedural problems, and the UNCSGN also decided that it will not make a decision on the issue because a discussion about a specific geographical name is not suitable for the purposes of the conference. It is reported that the issue is to be referred to a conference among the countries concerned hereafter.
The Korean Government has been raising this issue since the Sixth UNCSGN in 1992. The point of its allegations is that the term "Sea of Japan" was established when Japan colonized the Korean Peninsula, therefore this kind of imperialistic term should be abolished and the term should be renamed "East Sea," which is used in Korea, or at least both terms should be used. The Japanese Government opposes this argument, and says that the term "Sea of Japan" was established before the colonization of the Korean Peninsula, so it is nothing to do with imperialism.
In short, the contentious point of this issue is how the history of the term "Sea of Japan" is to be treated. Therefore, it is necessary to calmly assess what are historical facts.

Discovery and naming of the Sea of Japan

About 400 years ago in Beijing, Matteo Ricci, who was an Italian missionary priest of the Jesuit Order, produced a world map written in Chinese characters called Kunyu Wanguo Quantu (Konyo Bankoku Zenzu). The world map is the extant oldest map describing a sea area between Eurasia and the Japanese Islands using the term "Sea of Japan." The sea area was described as "the sea of Mangi," "the sea of Cin," or "the sea of China" on Western maps produced before Ricci's map. In other words, they were named after Chinese place names that typified the Eastern world. At that time, terms named after more specific place names, such as the Sea of Japan, or the Sea of Korea, were not yet used. No name was given to the sea area on Eastern maps.
In order to establish a certain term, an object that is described by the term must be identified. In the case of the Sea of Japan, it is essential to point out that the Sea of Japan, which is different from an expansive ocean to the east of the continent, was discovered as a marginal sea. In Kunyu Wanguo Quantu, Ezo Island was mistaken for Hokurikudo, but we notice that a closed sea area was described with the northern part of the Japanese Islands located closer to the continent. In fact, such awareness of geographical features started growing around the end of the 16th century, and Kunyu Wanguo Quantu was one of the earliest maps to indicate this.
Therefore, it is no coincidence that the term "Sea of Japan" appeared at this time. Because of the very fact that the Sea of Japan was "discovered" through such awareness of geographical features, conditions were ripe to give a name to the closed sea.

Popularization of the term "Sea of Japan"

The missionary spread the term "Sea of Japan" to Europe with a new awareness of geographical features. It is said that Kunyu Wanguo Quantu, which was sent by Matteo Ricci, is still kept now in the Vatican Library. In addition, maps and books written in European languages by those related to the Society of Jesus were circulated, and maps with the term "Sea of Japan" started to be drawn in Europe based on them.
Of these maps still in existence, the term "Sea of Japan" was first adopted by Christopherus Blancus who made a map of Japan in 1617. After that, the term "North Sea of Japan" was adopted by Sir Robert Dudley in 1646, while the term "Sea of Japan" was adopted by Vincenzo Maria Coronelli in 1690, then by Nicolaas Witsen in 1692, and gradually started to gain currency in the 17th and 18th centuries. However, around this time, the terms "Sea of China" and "Sea of Korea" were also not used less often, and a particular term was not necessarily established. But from the end of the 18th century onward, the name of this sea area began to be standardized as the Sea of Japan.
Kunyu Wanguo Quantu was also introduced to Japan early on, but the term "Sea of Japan" was not established right away. The term was first used in Japan in 1802 when Saisuke Yamamura, a scholar who specialized in Western sciences by means of the Dutch language, made a map attached to a revised Sairan Igen, a form of geographic documentation. After that, the term "Sea of Japan" eventually started to be used mostly in maps for the study of Western sciences in Dutch. This trend resulted from the widespread adoption of the term "Sea of Japan" in Western maps drawn from the end of the 18th century onward, which were used as sources for the former maps. In other words, the term "Sea of Japan" was "imported."

Toward mutual understanding of historical awareness

Against this historical background, the term "Sea of Japan" began to spread in Europe, the U.S., Japan and other areas. The International Hydrographic Organization (IHO) adopted the term "Sea of Japan" as an international term in 1929 based on this historical background and the international situation. Accordingly, Japan's Imperialism is not directly related to the establishment and popularization of the term "Sea of Japan." However, it is also true that the Korean Peninsula was under Japan's colonial rule in 1929 when the international agreement was concluded.
If the countries concerned are to proceed with discussions about this problem in the future, it is essential to readily accept these historical facts and to understand each other's historical awareness. Toward that purpose, the Japanese Government should patiently explain the historical facts about the term "Sea of Japan" while giving due consideration to the circumstances of the time when the international agreement was concluded. We are still not at the stage of considering an alternative term.