In 1875, the Japanese imperialists intruded the warship "Unyo-maru" to scout the military structures built on Kanghwa Island lying in the seaway to Seoul, capital city of the Feudal Joson Dynasty (1392-1910). But it was defeated by the garrison of the island.

Later, the Japanese imperialists raided the coast of Pusan with several warships aboard 800 troops and coerced the feudal government into a negotiation, while pounding the island.

The feudal government, which had not enough force to defeat the invasion, had no option but to sign the treaty worked out by the Japanese imperialists.

Through the conclusion of the treaty, the Japanese imperialists could tighten their economic grip on Korea and pave the way for invasion of it while imposing limitations to the feudal government's exercise of its sovereignty.