The Japanese 1870 Secret Report on Chosun (Korea)
“…How Ulleungdo and Dokdo became Chosun Possessions…” (竹島松島朝鮮附屬)

The following page is yet another record proving the Japanese Government (Meiji) considered Dokdo Island as part of Chosun (Korea). Dokdo Island is sometimes called Liancourt Rocks by western nations and Takeshima by Japan. Most websites regarding the Dokdo dispute include the 1870 Secret Mission Report about how Ulleungdo and Dokdo became Chosun’s possessions. However, most of them post only the relevant passage shown below. But the report was more than just proof the Ulleungdo and Dokdo were the possessions of Chosun. This secret report and its motivation for being instigated, gives us an inside look into the real intentions of the Japanese government during Chosun’s Opening of Ports Era.

Top left: An image of the original Kanji script form of the ‘Secret Report on Chosun’ Top right; The text form of the report clearly shows the passage 竹島松島朝鮮附屬 translated this means “How Ulleungdo and Dokdo became Chosun’s Possessions.” It then gives a brief historical overview of the islands.
The Origin of the Japanese Report on Chosun (Korea)
During the formative years of the Meiji Government Japan actively began to develop new diplomatic relations with Chosun. This first diplomatic mission included Moriyama Sigeru, Sada Hakubo and Saito Ei. This mission was to gather information for a few purposes such as 1. Finding out why the relationship between Japan and Chosun has deteriorated 2. Discontinue Tsushima’s payment of tributes to Chosun. 3. Investigate Chosun’s relationship with China. 4. Sending warships to Busan when the emperor dispatches his emissary to Chosun. 5. Find out if Chosun is being influenced by shrewd Russian diplomats. 6. Find out the strengths and weaknesses of the Chosun’s weaponry and navy. 7. Verify intelligence concerning the political situation of the Korean king and members of the Chosun court. 8. Potential trade with Chosun. 9. Investigate the customs and systems of Chosun.

Above left: A closeup picture of Ulleungdo (竹島) and Dokdo (松島) This is a typical Japanese map of the mid-19th Century showing the islands as they had for over a century prior to the 1870 Report on Chosun.
An Analysis of Japan’s 1870 Report on Chosun (Korea)

It is interesting that these instructions indicate the ambition and assertiveness of the Japanese politicians of the day. We can see the report is made from an unfriendly point of view. So what did the study mission report to the Foreign Ministry? The officials stayed in Korea from February 22, 1870 through early March and made their report in April. First the report states that Chosun does not maintain a tributary relationship with Japan. Second, Tsushima is apparently a vassal in the Korean system and has received copper seals (tosa, tosho) from Korea. Third regarding the question of China the Japanese mission reports that Chosun is operating independently of China.

At the end of the report there is a detailed history of the regarding possession of Ulleungdo and Dokdo by Chosun it states.

“…竹島松島朝鮮附屬 “How Takeshima (Ulleungdo) and Matsushima (Dokdo) became Korean Possessions…”

“…Matsushima (Dokdo) is a neighbor island of Takeshima (Ulleungdo) and there is no document on file by the shogunate concerning this (these) island(s). 2. The island of Takeshima (Ulleungdo) was settled by the Korean people after the 1690s (During the reign of King Sukjong) but it now has become uninhabited…..”

In addition, this report contained detailed plans for an attack on Chosun. The instructions called for an elaborate invasion of 30 battalions with the main force to land on Kangwha Island and to strike directly at Seoul. Subsiduary forces were to move South through the provinces of Kyongsan, Cholla and Chungchong and North through Hamyong, Pyongan and Hwanghae. Once these forces converged on Seoul, the Korean government was sure to collapse if the Chinese were to intervene the Japanese forces could handle them easily. The whole operation Sada Hokubo concluded would take about 50 days.

Sada Hokubo wrote:

“…If Imperial Japan passes this great opportunity to the foreigners, we will lose our lips (ie Korea) and then our teeth will surely suffer from the cold. Korea is a gold mine and wheat and rice are abundant. With one sweep we can mobilize the manpower, the mineral resources and the grain in Korea and use them in Hokkaido…..”

This document foreshadows the Japanese attack on Kangwha Island on September 20, 1875. The intrusion would set the wheels in motion for a series of unfair treaties and the gradual occupation of Korea.

Mapping Errors and the 1870 Chosun Report – Japan’s Implausible Refutation
With the mapping errors that occurred during this era some Japanese now assert that this document refers to other islands but this is not plausible. First, the historical reference in the 1870 Secret Report on Chosun mentions the Takeshima (竹島) of the Genruko Era. This would be Ulleungdo Island of course because only Ulleungdo could be settled on. Also it was Ulleungdo Island that was the object of a dispute between Chosun and Japan in the late 1690’s (ie the Anyongbok Incidents)

The only issue of contention is the identity of Matsushima (松島). Japanese lobbyists insist the Matsushima in this record is a different island. The 1870 report mentions that Matsushima was a neighbour island (隣島) of Ulleungdo. Was there another island near Ulleungdo refered to Matsushima (松島)? When we cite maps of the era, the Japanese “interpretation” of this important document can be dismissed as false.

Were the Japanese talking about a different Matsushima (松島) in this report, or did they continue to use the same name for Dokdo Island as they had for 200 years prior? The Japanese maps of the East Sea (Sea of Japan) and Ulleungdo, clarify this disagreement.

Early Meiji Era Japanese Maps Depicting Matsushima – (松島) Dokdo

Kashihara Yoshinaga’s 1876 Map of Japan and Korea

The map to the right of this text was drawn by Kashihara Yoshinaga in 1876 and is typical of Japanese maps of the East Sea (Sea of Japan) showing both Ulleungdo (竹島) and Dokdo (松島). As with all Japanese national maps, the shape of Dokdo (松島) is incorrect. No Japanese maps, aside from the private charts drawn by the Murakawa or Oya fishing clans depicted Dokdo in its correct two islet form, but rather vaguely traced an outline based on preceding maps.

The position of Ulleungdo is more westerly due to the influence of European charts. Most importantly Ulleungdo is labelled as “日本 (Japanese) name Takeshima (竹島) and 朝鮮 (Korean) name Ulleungdo…”No other islands exist in the East Sea on this map. Confirming the identity of Matsushima – 松島 as Dokdo Island. An abbreviated form of Saito Hosen’s “…Viewing Korea from here is similar to viewing Oki from Onshu…” (見高麗如雲州望-州) is drawn next to Matsushima – 松島 (Dokdo Island) as had been the case for over a century prior. (click picture for larger image)

An 1870 Report On Chosun’s Ulleungdo (竹島) and Dokdo (松島)
At the same time of the 1870 Report on Chosun, a study of Ulleungdo Island (referred to as Takeshima 竹島) was published and went into great detail about Korea’s Ulleungdo and the surrounding waters. Both the maps and description of Matsushima are consistent with Dokdo Island. This record excludes the possibility Matsushima – 松島 was one of Ulleungdo’s surrounding minor rocks, such as tiny Jukdo Islet located 2.2kms northeast of Ulleungdo.

The maps included with this report show both Ulleungdo’s neighbouring rocks and islets as well as a larger map of the East Sea (Sea of Japan) To further confirm the islands’ identity Saito Hosen’s 1667 quote “見高麗如雲州望-州” is drawn next to Ulleungdo and Dokdo. Take notice that this map is strangely oriented with West to the top of the page and East at the bottom. Thus, South and North are drawn left to right.

A map provided with a report on Takeshima ((竹島- Ulleungdo) shows no other islands west of Shimane Prefecture other than Dokdo (Matsushima – 松島)
As mentioned, included within the report on Ulleungdo was a highly detailed map of Ulleungdo itself. This map of Ulleungdo can be seen to the left. The island is drawn askew with North and South being positioned diagonally. Notice how Ulleungdo is labelled as Takeshima (竹島) on the bottom right.

Looking closely, all of Ulleungdo’s surrounding rocks and minor islets are included. Some rocks such as Chotdae Rock, Three Angels Rocks, Bukjeo Rock and Seal Point can all be located on this detailed map. However, nowhere within this map is there any adjacent islet named Matsushima. Only on the overall map of the East Sea is there an island referred to as Matsushima. This of course, would be Dokdo Island.

Pooling all of the related data, how some Japanese can maintain the position Matsushima was different island other than Dokdo remains a mystery. There doesn’t seem to be one piece of historical data to support this theory. More than likely this theory is an excuse to disregard a critical piece of historical data that essentially amounts to a “stake in the heart” for Japan’s MOFA’s claims of historical ownership over Dokdo Island.

The 1877 Kobunruko Documents Attached Map of Ulleungdo and Dokdo Island
In the year 1877 Shimane Prefecture inquired to the Home Ministry if Ulleungdo and another island (Dokdo) should be placed under their administrative control. The purpose of this inquiry was to determine which territories were included before mapping Japan. Attached to the 1877 document was an attached map showing Ulleungdo and Dokdo Island On this map the shape of Dokdo was drawn in the correct form as two islets. We can also Dokdo correctly labelled as (松島 – Matsushima)

The map provided with Meiji’s Kobunruko Documents shows Dokdo Island as (松島 – Matsushima) This map also showed no other islands and marked Ulleungdo’s Jukdo Islet as Igashima or “Squid Island” (click maps)
If we expand these charts to their largest size, it becomes apparent Ulleungdo Island has some neighbout islets drawn vaguely around the main island. Most notably, Jukdo Islet is depicted on Ulleungdo’s northeast shore. However, this island is not marked as Matsushima but rather Igashima or Squid Island. Many Japanese fishing records describe Ulleungdo’s Jukdo Islet as Igashima thus ruling out the possibility Jukdo Islet was the “Matsushima (松島)” of Japan’s 1870 Report on Chosun.

A 19th Century Japanese Map of Ulleungdo, Dokdo and Japan’s West Coast

The map to follow is important for a few reasons. First it records the illicit voyages of Japanese fishermen onto Chosun land originating from Yonago City. Ulleungdo and Dokdo are drawn in correct form and name. This chart correctly depicts Dokdo Island as two islets en route to Korea’s Ulleungdo Island.

Also this map enforces the fact that the Japanese perceived no extra islands in the East Sea outside of Ulleungdo (Takeshima-竹島)and Dokdo (Matsushima-松島) Like the Kobunroko map, Ulleungdo’s Jukdo Islet is labelled as Igashima or Squid Island. Therefore Japanese “historians'” claims there was another Matsushima Island next to Ulleungdo, are not true. (click map for large image)

The 1870 Report on Chosun – A Conclusion Based on the Evidence
Japan’s Early Meiji Government Clearly Considered Dokdo Island as Chosun Land
The 1870 Report on Chosun strongly damages Japan’s claim to Dokdo despite flimsy attempts by Takeshima lobbyists to dismiss this clear evidence of Japanese acquiesence of the island. There is no evidence to support Japanese claims that the Foreign Ministry was referencing incorrect maps or was referring to another fictitious Matsushima when they issued this report.

“…Here in this historical document its clear proof that Japan recognized Dokdo along with Ulleungdo as territories of Chosun. Japan used the expression “how Uleungdo and Dokdo became possessions of Chosun”. It is also clear that Japan believed Dokdo was associated with Ulleungdo and that there was an agreement during the 1690s which affirmed the two islands belonged to Chosun…”