Sakhalin Oblast

Sakhalin Oblast (Russian: Сахали́нская о́бласть, romanized: Sakhalinskaya oblastʹ, IPA: [səxɐˈlʲinskəjə ˈobləsʲtʲ]) is a federal subject of Russia (an oblast) comprising the island of Sakhalin and the Kuril Islands in the Russian Far East. The oblast has an area of 87,100 square kilometers (33,600 sq mi). Its administrative center and largest city is Yuzhno-Sakhalinsk. As of the 2021 Census, the oblast has a population of 466,609.

The vast majority of the oblast's residents are ethnic Russians, with a small minority of Sakhalin Koreans. Sakhalin Oblast is rich in natural gas and oil, and is Russia's second wealthiest federal subject after the Tyumen Oblast. It borders by sea Khabarovsk Krai to the west and Kamchatka Krai to the north, along with Hokkaido, Japan to the south.

The etymology of Sakhalin can be traced back to the Manchu hydronym Sahaliyan Ula (Manchu: ᠰᠠᡥᠠᠯᡳᠶᠠᠨ
ᡠᠯᠠ) for "Black River" (i.e. the Amur River). Sakhalin shares this etymology with the Chinese province of Heilongjiang (Chinese: 黑龍江; pinyin: Hēilóngjiāng; lit. 'black dragon river').

The indigenous people of Sakhalin are the Nivkh, Orok, and Ainu minorities.

The first Europeans to explore the waters around Sakhalin Island were Ivan Moskvitin and Martin Gerritz de Vries in the mid-1600s, Jean-François de La Pérouse in 1787 and Adam Johann von Krusenstern in 1805. Early maps of Sakhalin reflect the uncertainty of the age as to whether or not the land mass was attached to the Asian continent. The fact that it is not connected was conclusively established by Mamiya Rinzō, who explored and mapped Sakhalin in 1809 and definitively recorded by Russian navigator Gennady Nevelskoy in 1849.

Japanese settlement on Sakhalin dates to at least the Edo period. Ōtomari was supposedly established in 1679, and cartographers of the Matsumae domain mapped the island, and named it "Kita-Ezo". During the Ming and Qing dynasties China considered the island part of its empire, and included the Sakhalin peoples in its "system for subjugated peoples". At no time though was any attempt ever made to establish an Imperial military presence on the island. Japan, concerned about Russian expansion in northeast Asia, unilaterally proclaimed sovereignty over the whole island in 1845. Russian settlers ignored the claim (and the similar claim of China), however, and, beginning in the 1850s, established coal mines, administration facilities, schools, prisons and churches on the island.

In 1855, Russia and Japan signed the Treaty of Shimoda, which declared that both nationals could inhabit the island: Russians in the north, and Japanese in the south, without a clear boundary between. Russia also agreed to dismantle its military base at Ōtomari. Following the Second Opium War, Russia forced the Qing to sign the Treaty of Aigun and Convention of Peking, under which China lost all territories north of Heilongjiang (Amur) and east of Ussuri, including Sakhalin, to Russia. A Czarist penal colony was established in 1857, but the southern part of the island was held by the Japanese until the 1875 Treaty of Saint Petersburg, when they ceded it to Russia in exchange for the Kuril islands. After the Russo-Japanese War, Russia and Japan signed the Treaty of Portsmouth of 1905, which resulted in the southern part of the island below 50° N passing to Japan; the Russians retained the other three-fifths of the area. South Sakhalin was administered by Japan as Karafuto-chō (樺太庁), with the capital Toyohara, now known as Yuzhno-Sakhalinsk.

After the Russian Revolution and subsequent civil war northern Sakhalin ultimately became governed by the Russian SFSR as a part of Far Eastern Oblast (1922–1926), Far Eastern Krai (1926–1938) and Khabarovsk Krai (included Russian-administered territories of Sakhalin in 1938–1947). Sakhalin Oblast was established on 20 October 1932 as a part of Far Eastern Krai, and became part of Khabarovsk Krai upon the latter foundation in 1938.