evidence: The landlocked mountainous region of Nagorno-Karabakh was the subject of a long-standing territorial dispute between Azerbaijan, in which it lies, and its ethnic Armenian majority, backed by neighbouring Armenia. [...] 1920s - After the end of World War One and the Bolshevik revolution in Russia, the new Soviet rulers, as part of their divide-and-rule policy in the region, established the Nagorno-Karabakh Autonomous Region, with an ethnic Armenian majority, within the Soviet Socialist Republic of Azerbaijan. [...] 2020 - Second Karabakh war: Azerbaijan launches an offensive that recaptures territory around Karabakh. Some 3,000 Azerbaijani soldiers and 4,000 Armenian soldiers are killed in six weeks of fighting.