In 1920-21 the only "solution" to this dispute could come either by military victory—as basically happened in Anatolia, Zangezur and Nakhchivan—or by the imposition from above of a new structure by an imperial power. After the British failed to impose a settlement, the imperial arbiters turned out to be the Bolsheviks, whose 11th Army conquered Karabakh in May 1920. On 5 July 1921 the Bolsheviks' Caucasian committee, the Kavbiuro, under the chairmanship of Joseph Stalin ruled that the mountainous part of Karabakh would be part of Azerbaijan. In July 1923 the Nagorny  Karabakh Autonomous Region  was created within Azerbaijan, with borders that gave it an overwhelming Armenian majority of 94% of the total inhabitants.
Question: What happened first, Joseph stalin ruled the mountainous part of Karabakh or the imperial arbiters turned were Bolsheviks?
Answer: imperial arbiters turned were Bolsheviks