Japan–Korea Treaty of 1876 in the context of "Korean Peninsula"

From 1910 to 1945, Korea was ruled by the Empire of Japan as a colony under the name Chōsen (朝鮮), the Japanese reading of "Joseon".

Japan first took Korea into its sphere of influence during the late 1800s. Both Korea (Joseon) and Japan had been under policies of isolationism, with Joseon being a tributary state of Qing China. However, in 1854, Japan was forcibly opened by the United States. It then rapidly modernized under the Meiji Restoration, while Joseon continued to resist foreign attempts to open it up. Japan eventually succeeded in forcefully opening Joseon with the unequal Japan–Korea Treaty of 1876.

Gojong (Korean: 고종; Hanja: 高宗; 8 September 1852 – 21 January 1919), personal name Yi Myeongbok (이명복; 李命福), later Yi Hui (이희; 李㷩), also known as the Gwangmu Emperor (광무제; 光武帝), was the penultimate Korean monarch. He ruled Korea for 43 years, from 1864 to 1907, first as the last king of Joseon, and then as the first emperor of the Korean Empire from 1897 until his forced abdication in 1907. His wife, Queen Min (posthumously honored as Empress Myeongseong), played an active role in politics until her assassination carried out by the Japanese.

Gojong oversaw the bulk of the Korean monarchy's final years. He was born into the ruling House of Yi, and was first crowned on 13 December 1863 at the age of twelve. His biological father, Grand Internal Prince Heungseon (widely known as Heungseon Daewongun), acted as regent until he reached the age of majority, although he continued holding power until 1874. At this time, Korea was under policies of strict isolationism. By contrast, Japan had been rapidly modernizing under the Meiji Restoration. In 1876, Japan forcefully opened Korea and began a decades-long process of moving the peninsula into its own sphere of influence. For the following few decades, Korea was highly unstable, and subjected to a number of foreign encroachments. Incidents such as the 1882 Imo Incident, the 1884 Kapsin Coup, the 1894–1895 Donghak Peasant Rebellion, and the 1895 assassination of Gojong's wife occurred during his reign. All of these incidents were related to or involved foreign powers.

The Anglo-Japanese Alliance (日英同盟, Nichi-Ei Dōmei) was an alliance between the United Kingdom and the Empire of Japan which was effective from 1902 to 1923. The treaty creating the alliance was signed at Lansdowne House in London on 30 January 1902 by British foreign secretary Henry Petty-Fitzmaurice, 5th Marquess of Lansdowne and Japanese diplomat Hayashi Tadasu. After the preceding era of unequal treaties enforced on Asian countries including Japan, the alliance was a military pact concluded on more equal terms between a Western power and non-Western nation. It reflected the success of Meiji era reforms that modernized and industrialized Japan's economy, society and military, which enabled Japan to extract itself from the inferior position it had previously shared with other Asian countries like China, which had been subordinated to Western empires either through formal colonial acquisition or unequal treaties.

One shared motivation for the agreement was that a diplomatic alliance might deter other world powers that might otherwise encroach on British and Japanese imperial interests in Asia. For the British, the alliance marked the end of a period of "splendid isolation" while allowing for greater focus on protecting its rule over India and competing in the Anglo-German naval arms race, as part of a larger strategy to reduce imperial overcommitment and recall the Royal Navy to defend Britain. By contrast, it came at a time of Japan's ascendancy; Japan had not only successfully abrogated the unequal treaties it was previously subject to by the Western powers, but was now a fledging empire in its own right: Japan had imposed its own unequal treaty on Korea in 1876 and now controlled Formosa (Taiwan) as a colony, as Taiwan been ceded by Qing China to Japan in the Treaty of Shimonoseki, after the First Sino-Japanese War. Consequently, Japan was now developing its own imperial sphere of influence, and felt that a conflict with Russia was imminent over rival ambitions in Manchuria and Korea, especially after the Triple Intervention in 1895, in which Russia, France, and Germany coerced Japan into relinquishing its claim on the Liaodong Peninsula. Article 3 of the alliance promised support if either signatory became involved in war with more than one power, and thus deterred France from assisting its ally Russia in the Russo-Japanese War of 1904–1905. Instead, France concluded the Entente Cordiale with Britain and limited its support of Russia to providing loans. Japan also gained international prestige from the alliance and used it as a foundation for their diplomacy for two decades, although the alliance angered the United States and some British dominions, whose opinion of Japan worsened and gradually became hostile.