The Name “Sea of Japan” Is the Only Internationally Established Name(The Debate Concerning the Naming of the Sea of Japan - Analysis of the South
Korean Government’s Arguments based on Historical Materials and Maps-)
Masao Shimojo
Professor, Takushoku University
1. Introduction
Disagreement about the naming of the Sea of Japan has persisted between Japan andSouth Korea since the sixth UN Conference on the Standardization of GeographicalNames (UNCSGN) in 1992. During this time, the Japanese government has consistentlymaintained that “the name Sea of Japan is the only internationally established name.”
Probably because the government of South Korea thought that it would be difficult toget agreement to use “East Sea” as the sole name, they have been arguing that both “Seaof Japan” and “East Sea” should be simultaneously used since the 1997 conference ofthe International Hydrographic Organization.
US President Trump used the word “Sea of Japan” when he spoke to U.S/ sailors
aboard a US navy vessel at the Yokosuka base on May 28. His reference to the Sea ofJapan was widely reported by the South Korean media and, at a press conference, SouthKorean Foreign Ministry Spokesperson Kim In-chul stated that the name “East Sea”
must be used alongside the name “Sea of Japan.” According to the South Korean
media, a U.S. Department of State spokesperson stated that the US government uses
only one name decided by the US Board on Geographic Names to refer to all high seasfeatures and the name approved by the Board for the body of water between Japan andKorea is the Sea of Japan.
The reason why Seoul continues to insist on the name “East Sea” is because theSouth Korean government, which has occupied the Japanese territory of Takeshima(Korean name of Dokdo) since 1954, has associated the territorial issue with the namingof the Sea of Japan. Part of the South Korean side’s logic for justifying the name “EastSea” is that, if Dokdo (Takeshima) is in the Sea of Japan, then it is inappropriately
appears as if Dokdo is in Japanese territorial waters. In this regard, the South Korean
government has claimed that the name “East Sea” has been used for 2000 years andshould be used instead of the name “Sea of Japan”.
The basis for the claim that the name “East Sea” has been used for 2000 years is thephrase “beaches of the East Sea” from the Book of the Sage King Tongmyŏng of the1

Koguryŏ 1 Annals ( 高句麗本紀始祖東明聖王条 ) in the Samguk sagi ( 三国史記 ,history of the three kingdoms). The South Korean side also argues that the reason why
the name “East Sea” was excluded from the Limits of Oceans and Seas of theInternational Hydrographic Organization in 1929, in spite of the use of the name for2000 years before that, is that Korea was under Japanese rule at that time and thus
deprived of the opportunity to assert the legitimacy of the name” East Sea”.
However, as discussed in detail below, the word 東海 (Donghae, Dong means Eastand Hae means Sea) that appears in the Samguk sagi, the Kwanggaet’o Stele (広開土王碑,a stone monument erected in 414), the P’alto ch’ongdo (八道総図, complete map ofthe eight provinces), the Aguk ch’ongdo (我国総図, complete map of Korea), and otherpieces of evidence2 that have been identified by the South Korean government do notrefer to the Sea of Japan. For instance, the word “Donghae” in the Aguk ch’ongdo only
refers to the eastern coastal waters off the Korean peninsula (not whole part of the Seaof Japan.) In the case of “beaches of the East Sea (東海之濱)” from the Samguk sagi,
the word “Donghae” refers to the Yellow Sea or the East China Sea. “Donghaemerchants (東海賈)” in the Kwanggaet’o Stele refers to merchants in the place called
Donghae. The word “Donghae” in the P’alto ch’ongdo signifies ritual sites (DonghaeShrine) on the ground. The word 東海 (Donghae) appeared in these pieces has nothing
to do with the body of water called the Sea of Japan as determined by the International
Hydrographic Organization in Limits of Oceans and Seas. As such, it does not qualify asan alternative to the name “Sea of Japan”.
2. “East Sea” in the Aguk ch’ongdo
For example, in the case of the Aguk ch’ongdo, it is true that it mentions “Donghae(East Sea)” to the east of the Korean peninsula, but the western and southern coastal
waters off the Korean peninsula are also indicated as “Seohae (西海, West Sea)” and“Namhae (南海, South Sea),” respectively. Seohae is part of the Yellow Sea andNamhae is a part of the East China Sea, so they are names for stretches of the Korean
peninsula’s coastal waters. In light of the South Korean government’s argument that
“East Sea” should be used instead of “Sea of Japan”, it would be natural that Seoul
would also claim that the names “Yellow Sea” and “East China Sea” should be replaced
1

Koguryŏ is one of the three kingdoms whose historical record is compiled in theSamguk sagi. It was found in the area north to the Yalu River in the 1st Century BCand expanded its territory to a part of both the Korean Peninsula and northeast China.
2 For the view of the South Korean Ministry of Foreign Affairs, see
http://www.mofa.go.kr/www/wpge/m_3838/contents.do2

by the names “West Sea” and “South Sea” respectively, but Seoul is making no suchdemands. The only reason why the South Korean government takes issue with the Seaof Japan is because that is where the Takeshima (Dokdo) is located.

Aguk ch’ongdo (我国総図, complete map of Korea)
In the Aguk ch’ongdo, in addition to “Donghae (東海, East Sea)” to the east of theKorean peninsula, the western and southern coastal waters off the Korean peninsula are
indicated as “Seohae (西海, West Sea)” and “Namhae (南海, South Sea),” respectively.
In light of the logic by the South Korean government, it should have taken issue withSeohae and Namhae, too. But it has not done so.
3Moreover, the fact that “East Sea” in the Aguk ch’ongdo refers to only the stretches of
the Korean peninsula’s eastern coastal waters can be verified by the Map of Liaodongand Korea ( 遼東連朝鮮図 ) in the Haifang zuanyao ( 海防纂要 , Compilation on
Maritime Defenses) , compiled by Wang Zaijin of the Ming. There, the western coastal
waters off the Korean peninsula is indicated as “Korean West Sea (朝鮮西海),” thesouthern coastal waters as “Korean South Sea (朝鮮南海),” and the eastern coastalwaters as “Korean East Sea (朝鮮東海.)” They only mean the coastal waters off theKorean peninsula. Thus, the South Korean government’s claims that “East Sea” in theAguk ch’ongdo refers to the whole area of the Sea of Japan are nothing other than anarbitrary interpretation of the map.

The Map of Liaodong and Korea (遼東連朝鮮図) in the Haifang zuanyao
4(海防纂要, Compilation on Maritime Defenses)
3. The “Beaches of the East Sea” from the Samguk sagi
We can see another case of the South Korean government’s arbitrary interpretationsof literature in its claims with respect to the phrase “beaches of the East Sea” from
Koguryŏ Annals of the Samguk sagi, which is taken as evidence that the word “EastSea” has been used since 2,000 years ago. The South Korean government does not
doubt that Koguryŏ is part of Korean history, but China perceives Koguryŏ as a Chinese
regional kingdom. From the perspective of Chinese, the word “East Sea” of the phrase“beaches of the East Sea” refers to the Yellow Sea or the East China Sea.
Now, where were the “beaches of the East Sea” located? In the Samguk sagi, thephrase “beaches of the East Sea” were used to refer to area where the Sage KingTongmyŏng, the founder of Koguryŏ, moved to established his new state. If so, weshould be able to infer where the “East Sea” was based on the territory of Koguryŏ at
the time of its founding. Taking a look at entries about Koguryŏ in books such as the“Treatise on Geography (地理志)” in the Hanshu (漢書, Book of Han) , the “Treatiseon Geography” in the Hou Hanshu (後漢書 Book of the Later Han,) and the “Recordsof Wei: An Account of the Easterners (魏志東夷伝 )” in the Sanguozhi (三国志 ,Records of the Three Kingdoms)3 , Koguryŏ was founded near the upper reaches of theYalu River in the 1st Century BC. The area to the east of Koguryŏ was occupied by
Eastern Okchŏ (東沃沮). In other words, at the time of its founding, Koguryŏ’s territory
was not adjacent to the Sea of Japan.
In fact, according to the Koguryŏ Annals of the Samguk sagi, Koguryŏ did not defeat
Eastern Okchŏ, expand its territory eastward, and reach the Sea of Japan until the reignof King T’aejo(太祖), sixth generation after the Sage King Tongmyŏng4. The “East Sea”
in the Samguk sagi, based on which the South Korean government asserts that the nameAccording to “an Account of Koguryŏ” of the “Records of Wei: An Account of theEasterners” in the Sanguozhi, and “An Account of the Easterners” in the Hou Hanshu,“Koguryŏ lies to the east of Liangdong, with Korea and the Yemaek to the south, the Okchŏ tothe east, and Puyŏ to the north (高句麗在遼東之東、南與朝鮮、濊貊、東與沃沮、北與夫餘接).” According to “an Account of Eastern Okchŏ” of the “Records of Wei: An Account of theEasterners” in the Sanguozhi, “Eastern Okchŏ is to the east of the Kaema Mountains in Koguryŏ,by the eastern shore [facing] the great sea (東沃沮、在高句麗蓋馬大山之東、東濵大海.)”
4
According to the Record of Seventh month in the fall of the 4th year of the reign of King
T’aejo (太祖大王四年秋七月条), Koguryŏ Annals, Samguk sagi, “They attacked EasternOkchŏ, took their land, towns, and villages, and expanded their borders to the Blue Sea in theeast (伐東沃沮、取其土地為城邑、拓境、東至滄海).”35

“East Sea” has been in use since 2,000 years ago, was not the Sea of Japan.

The Koguryŏ Annals (高句麗本紀) of theSamguk sagi( 三国史記 , history of thethree kingdoms)“Records of Wei: An Account of theEasterners ( 魏 志 東 夷 伝 )” in theSanguozhi (三国志, Records of the ThreeKingdoms)

4. The “Donghae Merchants” on the “Kwanggaet’o Stele”
Now, what about the word “Donghae” on the “Kwanggaet’o Stele,” erected in 414?
The “Kwanggaet’o Stele” was erected by King Changsu (長寿王) of Koguryŏ to extol
the accomplishments of his father King Kwanggaet’o, so it is inscribed with tombkeepers to protect the tomb of King Kwanggaet’o as well as their numbers. Among
those keepers were the “Donghae Merchants5.” The South Korean government took

5

The passage around the phrase “Donghae Merchants” on the Kwanggaet’o Stele that6notice of the word “Donghae” of the phrase “Donghae Merchants” and assumed it tosignify the Sea of Japan.
However, the “merchants” called the “Donghae Merchants” mean “merchants” in theplace called Donghae (東海). The Chinese character “海” means not only “sea” but also
“direction.” That was the same in Korea and the character “海” was also used for namesof places on the ground. It is unclear where that Donghae was, but it is rather arbitrary
to assert that the “Donghae merchants” were those in the Sea of Japan without furtherevidences.

The “Donghae Merchants (東海賈)” on the “Kwanggaet’o Stele (広開土王碑,a stone monument erected in 414)”
The South Korean government pays attention to the word “Donghae (東海)” in the“Kwanggaet’o Stele” and assumed it to signify the Sea of Japan without taking into
account the context in which the word Donghae was used. The passage around the word
Donghae on the Kwanggaet’o Stele is “Of the Donghae merchants, three are kugyŏnhouseholds and five are kanyŏn households (東海賈國烟三看烟五 ).” That is, the“Donghae Merchants” mean “merchants” in the place called Donghae (東海), which
may be on the ground.

the Korean government has cited as evidence is “Of the Donghae merchants, three arekugyŏn households and five are kanyŏn households (東海賈國烟三看烟五).”7

5. The word “Donghae” in the P’alto ch’ongdo
The South Korean government regard the name “Donghae” in the P’alto ch’ongdo as
the Sea of Japan. Yet this is another distorted interpretation. The “P’alto ch’ongdo” is amap of all of Korea included in the Tongguk yŏji sŭngnam (東国輿地勝覧, Survey ofthe Geography of Korea). It shows large rivers like the Han River and the Yalu River aswell as the names “Donghae”, “Namhae (南海)”, and “Seohae (西海)” on the ground.
Seoul interpreted this “Donghae” as the Sea of Japan, but that is unfounded speculation.
That is because the afterword of the Tongguk yŏji sŭngnam specifies the following withregard to the P’alto ch’ongdo:“The comprehensive map in the beginning of the book (the P’alto ch’ongdo) is arecord of sacred peaks as well as famous mountains and large rivers listed in the RitualCodes (祀典).”The large rivers and the “Donghae” depicted in the P’alto ch’ongdo referred to thelocations where state rituals took place as prescribed in the Ritual Codes. In fact, the“Donghae” shown in the P’alto ch’ongdo marks the location of the “Donghae Shrine( 東海神祠 )” included in the “Yangyang District” Section ( 襄陽都護府条 ) of theTongguk yŏji sŭngnam. The “Donghae Shrine” was rebuilt in recent years as the“Donghae Sanctum (東海神廟),” as shown in the photo below, and the “Namhae” wasalso the “Nanhae Sanctum.” The “Donghae” in the P’alto ch’ongdo marked the locationof the “Donghae Shrine,” where state rituals took place, as specified in the afterword ofthe Tongguk yŏji sŭngnam. This “Donghae Shrine” cannot be interpreted as the Sea ofJapan.

8

The word “Donghae (東海)” in the P’alto ch’ongdo (八道総図, complete map of theeight provinces)

The “Donghae Sanctum (東海神廟),”that was rebuilt in recent years

The “Nanhae Sanctum”

9Moreover, regarding the Donghae, the afterword of the Tongguk yŏji sŭngnam statesthat “Each map of the eight provinces records the mountains guarding each area as wellas its four boundaries.” The maps depicting the administrative divisions bordering on
the Sea of Japan, “Hamgyŏng Province (咸鏡道),” “Kangwŏn Province (江原道),” and“Kyŏngsang Province (慶尚道),” all show their “four boundaries (四至四到)” andspecify the adjacent areas.
At the eastern edges of the maps of “Hamgyŏng Province,” “Kangwŏn Province,” and“Kyŏngsang Province” there is the notation “Great Sea to the east (東抵大海).” This isbecause, at that time, Korean differentiated between the coastal waters and the open sea,
which was called the Great Sea. This division between coastal waters and open sea
comes from the fact that the Tongguk yŏji sŭngnam was compiled according to the same
policy as the Da-Ming yitong zhi (大明一統志, Records of the Unity of the GreatMing.)
This tradition of differentiating between the two continued into modern times. PakŬnsik ( 朴殷植 ) wrote the following in his Painful History of Korea ( 韓国痛史 ,published in 1915):“Korea is a peninsular nation sticking out in the southeast of Asia. Its borders are[along] the Blue Sea (蒼海) and are separated from the Sea of Japan to the east as wellas the Yellow Sea facing the two Chinese provinces of Shandong and Jiangsu to thewest.”

10

“Kangwŏn Province (江原道),” in theTongguk yŏji sŭngnam ( 東国輿地勝覧 ,Survey of the Geography of Korea)

This was fourteen years before the International Hydrographic
Organization determined the names of the oceans and seas. Thisshows that the Blue Sea was considered the coast waters off theKorean peninsula and the Sea of Japan the open sea offshore at thattime. This is also indicated by the wording “the East Sea, also known
as the Blue Sea, a part of the Sea of Japan” in an article in theDong-A Ilbo (東亜日報), dated July 1, 1926. The South Korean
government argues that Korea was unable to assert the East Sea namein 1929 as it was under Japanese colonial rule, but at the time of theSea of Japan’s inclusion in the Limits of Oceans and Seas, East Sea
was used in Korea as a name for coastal waters off the Korean
peninsula. It was only after WWII that East Sea came to be used for
the Sea of Japan. An article in the Dong-A Ilbo, dated June 15, 1946,had the headline “East Sea or Sea of Japan?” but that was because adebate about whether to call the Sea of Japan the East Sea just hademerged.

11Painful History ofKorea (韓国痛史,published in 1915)
written by Pak
Ŭnsik (朴殷植)

6. The Name “Sea of Japan” was Used also in the Korean Peninsula in the Second
Half of the Nineteenth Century
Seoul repeatedly argues that the names “Sea of Japan” and“East Sea” should be used side by side because “East Sea” hasbeen used since 2,000 years ago. But it was not until around themid-twentieth century that the Sea of Japan came to be called
the East Sea in the Republic of Korea.
As mentioned above, the Korean patriot Pak Ŭnsik differentiatedbetween the Sea of Japan and the Blue Sea in his Painful History ofKorea. That we because the name “Sea of Japan” had been usedalso on the Korean peninsula since the second half of thenineteenth century. The Yŏlchae ch’waryo (輿載撮要) from 1896
states that Korea “is in eastern Asia. It borders the Bohai Sea ofthe Qing to the west. It is connected with Manchuria to the north,and is demarcated by the Sea of Japan to the east.” Also theTae-Han chiji ( 大韓地 誌 , Atlas of the Great Korean Empire,The Dong-A Ilbo (東亜日published 1899), translated, edited, and compiled by Hyŏn Ch’ae (玄 報), dated July 1, 1926
采) of the Korean Empire, states that Korea is “demarcated by theSea of Japan in the east and [along] the beaches of the Yellow Sea inthe west.”
As the South Korean government demands the name “Sea of Japan”
to be changed to “East Sea,” they emphasize the inappropriateness ofthe name Sea of Japan in light of Japan’s colonial rule. Yet, the nameSea of Japan was not decided solely by Japan. a cartographer in theJapanese Navy, in 1876, also says “日本海/JAPAN SEA,” but that isbecause it was drawn based on British sea charts. Subsequently, theTaiwan suiro shi (寰瀛水路誌, published 1883) and the Chosen suiroshi (朝鮮水路誌, published 1894) were also compiled by referring toBritish nautical charts, sticking with the name Sea of Japan.

The Yŏlchae ch’waryo(輿載撮要)12The Tae-Han chiji (大韓地誌, Atlas of the Great Korean Empire, published 1899)
7 Conclusion
The Japanese government’s statement that “Sea of Japan is the only internationallyestablished name” is based on consideration of the above-mentioned history. The South
Korean side’s emphasis on Japanese colonial rule is totally irrelevant here. Moreover, asI have discussed at length, the word 東海 (“Donghae”) that the South Korean
government brings up as evidence in their challenge against the name Sea of Japan waseither a coastal waters off the Korean peninsula, names of places on the ground, or theYellow Sea, or the East Sea of China. We should not refer to the Sea of Japan as the EastSea.
It is also inappropriate to use Sea of Japan and East Sea side by side as theinternationally established names.
13

The Complete Map of the Land and Sea of Great Japan, Along with Korea andKarafuto (日本海陸全国聯接朝鮮樺太) made by Ōjiri Hidekatsu (大後秀勝)
14