Ganghwa Island incident (江華島事件)

The Ganghwa Island incident is an armed conflict between Japan and Korea which occurred in the vicinity of Ganghwa Island, Joseon Dynasty on September 20, 1875. It is also known as Unyo Incident, which had its name from the Japanese warship "Unyo." As a result of this incident, Japan and Korea concluded the Japanese-Korea Treaty of Amity.

Background
In the second half of the Edo period, Japan opened its secluded economy to the world, and the New Meiji Government sent to the government of the Joseon Dynasty an envoy holding a letter with the sovereign's message which informed them of the founding of a new administration of Japan and requested to establish relations and start to trade on December 19, 1868. However, the Joseon Dynasty refused to receive the letter because it contained the Chinese characters '皇' (Royal, imperial) and '勅' (imperial decree) despite the fact that '皇' was allowed to be used only for the Chinese emperor and '勅' signified the imperial rescript under the tributary system.
After that, Japan sent them the letter with the sovereign's message again and again, but the Joseon Dynasty refused to receive on every occasion (it is called Shokei Mondai, the problem of letters.)

So Japan first concluded the Japan-Qing Treaty of Friendship with Qing. Afterward, the territorial problem occurred between Japan and Qing (see also The Taiwan Expedition), then Qing feared Japan's strong attitude and they directed the Joseon Dynasty to receive the letter. On this occasion, the negotiation was going to be reopened, but 相良正樹, the government official of the Ministry of Foreign Affairs, lost his patience because the negotiation was not proceeded at all, so he went to Toraifu, although he was prohibited to go out of Choryang-dong Wakan (the residence office of the Tsushima clan), and he demanded to meet with an ambassador of Toraifu in May of 1872 (go out of Wakan).

Further, in September of the same year, the name of this consulate was changed by Japan from Choryang-dong Wakan to Nihon Kokan (Japanese Consulate) and they also had the Ministry of Foreign Affairs manage this consulate in place of the Tsushima clan. This is because Choryang-dong Wakan was built by the Korean government as the facility for the Tsushima clan, the Tsushima clan was in a position of the window to negotiate between Japan and Korea, therefore Japan did the above acts.

Toraifu side was so angered by these acts that they stopped supply of food etc. to Nihon Kokan and also prohibited the trading activities by Japanese traders. Previously, it was said that on this occasion Korea did 'an insulting act against Japan,' which was reported to Japan side, but according to recent studies, it is cleared that this description of the report was an artificiality one.

However, these Toraifu's dealings had enough effect to stroke Japan's fur the wrong way, and it brought 'Seikanron' (insistence on making Korea open to the world by military power) in Japan.

Progress
In September of 1872, Yoshimoto HANABUSA came to Korea by the ship named Kasugamaru to interchange with the Tsushima clan, so Korea considered Japan a target under Eisei Sekija (Korea's foreign policy during this period to respect the justice and exclude the evil; in this case Japan was regarded as evil) as well as Western Europe. Heungseon Daewongun criticized Japan as follows.
Why did Japanese come to Korea by the steamboat and why do they put on western style clothes?'
These acts will disturb the Chinese Suzerainty over Korea.'
When the negotiation came up against unexpected difficulties, the issue of the dispatch of troops, like Seikanron, which demands the dispatch of troops to Korea, became a political issue in Japan. In 1873, the political change occurred and, as a result, it was decided to 'postpone' (not 'stop') the Seikanron dispute. However, because Seikanron lost its momentum due to the occurrence of the Taiwan expedition and the downfall of Heungseon Daewongun in Korea, the Meiji Government decided to observe Korea's condition.

In 1875, the negotiation was held between the Torai Government and Shigeru MORIYAMA in Pusan Metropolitan City for the first time. However the Torai government did not permit Japanese taishi (commander-in-chief) to put on the taireifuku (court dress, full-dress uniform) and pass the main gate when he participated in the dinner party. In addition, because at the center of the Korean government, the supporters of Daewongun demanded halting the negotiation, the discussions became complicated, and it also became impossible for the Torai government to give a firm reply to the Japanese government. The Japanese government was at the mercy of the Joseon Dynasty's diplomacy and they lost their patience at last, so they made a breakthrough; dispatched a small warship to Pusan and invited the members of Toraifu on board to show the shooting exercises.

The hard-liners of Japan suggested to Munenori TERASHIMA, Gaimu-taifu (post of Foreign Ministry) to dispatch a warship to inshore of Korea in the name of measuring the coastline and investigating passages (to harass them as well as Matthew [Calbraith] PERRY did), and he accepted it under the approval of Sanetomi SANJO, the Grand Minister, and Tomomi IWAKURA, Minister of the Right. Accordingly, Munenori TERASHIMA commanded Sumiyoshi KAWAMURA, Navy taifu (vice-minister), to dispatch two warships: "Unyo" and "Dainiteibo."

On May 25, Japanese warship sailed into Pusan without Korean permission and threatened Korea by showing the shooting exercise etc. Korea protested against these acts.

Regarding this incident, the traditional theory says that Yoshika INOUE, navy major, was sailing on the Japanese warship Unyo. To supply fresh water against shortage of drinkable water, Inoue himself boarded a small boat from the Japanese warship Unyo and was approaching the land. When they reached the offshore of Chojijin in Ganghwa Island, displaying the national flag of Japan in search of drinkable water, Korean garrison opened fire toward them from the third gun battery placed on Ganghwa Island. So he hurriedly came back to the Unyo and attacked and destroyed the gun batteries of the Island; then, he occupied the fort of the EisoJoto island.

However, in these days, the new material was found and it was inevitable to correct this theory. There was a doubt about the reliability of the traditional theory, because the official report (October) of Unyo, on which the traditional theory was based, originally describes that Japan and Korea battled for only one day (three days in reality). However, the official report (September) which was submitted nine days after the incident describes that Japan approached Korea's camp by warship to meet the Korea's bureaucrats for the purpose of measuring and so on, and when they advanced more (toward Seoul) without permission from Korea, they were attacked from Korea's gun battery. Sailing the rivers of foreign countries without permission is a violation of the international laws, and in this case, it was assumed that the Japanese army's act was provocation against Korea, because they were going to the capital.

On the day after Korea opened fire, Japan did the bombardment of land by their warships. Then they sent Naval Landing Forces and Marine Corps and Landing Forces of the Empire of Japan to set fire to the second gun battery. On the third day, they also set fire to the first gun battery and killed 35 Korean soldiers. On the other hand, the number of casualties for the Japanese was 2 of Unyo.

This incident brought such a terrible shock to the Korean government that they had to consider the recovery of the diplomatic relations with Japan by surmounting all objections by the supporters of expulsion of foreigners, and concluded the Japanese-Korea Treaty of Amity (the Treaty of Ganghwa) in 1876.