On 12 February 1991, the status of the Crimean Oblast was changed to that of autonomous republic by the Ukrainian SSR as the result of a state-sanctioned referendum held on 20 January 1991.

[1] Four months later, on June 19, appropriate changes were made to the Constitution of the Ukrainian SSR.

[2][3] In September 1991, the Crimean parliament declared the territory to be a sovereign constituent part of Ukraine.

The status of Sevastopol, due to its strategic importance as the main base of the Russian Black Sea Fleet, remained disputed between Ukraine and Russia until 1997 when it was agreed that it should be treated as a "city with special status" within Ukraine.

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