The territory of Crimea, previously controlled by the Crimean Khanate, was, for the first time, annexed by the Russian Empire on 19 April 1783. The period before the annexation was marked by Russian interference in Crimean affairs, a series of revolts by Crimean Tatars, and Ottoman ambivalence. Russian rule in Crimea, ended in 1954 and the territory was transferred to the Ukrainian Soviet Socialist Republic by decree of the Presidium of the Supreme Soviet of the Soviet Union. On 21 May 1992, the Supreme Soviet of Russia adopted a resolution, which declared Crimea’s 1954 transfer invalid and called for trilateral negotiations on the Crimea’s status. Confrontation between the president and parliament of Russia, ended with armed conflict in Moscow. Therefore, this resolution had no effect in Crimea or Ukraine. Russia annexed Crimea for a second time in March 2014.
The annexation of Crimea took place from 23rd February until 19th March 2014 during the Ukraine Revolution. The annexation started with pro-Russian demonstrations on 23rd February 2014 which were held in the Sevastopol. Four days later, masked Russian troops took up Supreme Council of Crimea, and seized several strategic sites all over the Crimea. All these occurrences led to adoption of the declaration of Crimea’s independence, and holding of an ilegal referendum. The referendum was condemned by many international organizations, such as NATO, United Nations, as an unlawful, violating the 1994 Budapest Memorandum on sovereignty and territorial integrity of Ukraine, signed by Russia. That caused temporarily suspension from the G8 group, and introducing the first round of sanctions against Russian Federation.
On the other side, The Russian President, Vladimir Putin, noted that the United Nations International Court of Justice handed down an advisory opinion in 2010 saying unambiguously that “ the unilateral declaration of independence in Kosovo (for which there was no referendum nor agreement from Belgrade) was not prohibited by international law”. The Partition Treaty on the Status and Conditions of the Black Sea Fleet signed in 1997 between Ukraine and Russia, and prolonged in 2010, determined the status of the military bases and vessels in Crimea. Russia was allowed to “ maintain up to 25,000 troops, 24 artillery systems (with a calibre smaller than 100 mm), 132 armored vehicles, and 22 military planes, on military base in Sevastopol and related infrastructure on the Crimean Peninsula”. The Russian Black Sea fleet had basing rights in Crimea until 2042. The annexation is not in accordance with the Chapter of the United Nations, ratified by Ukraine and Russia, which guarantees independence, sovereignty, self-determination, acts of aggression, and humanitarian emergencies.