Russian occupation of Crimea

On 27 February 2014, unmarked Russian soldiers were deployed to the Crimean Peninsula in order to wrest control of it from Ukraine, starting the Russo-Ukrainian War. This military occupation, which the Ukrainian government considers to have begun on 20 February, laid the foundation for the Russian annexation of Crimea on 18 March 2014. Under Russia, the Ukrainian Autonomous Republic of Crimea was replaced by the Republic of Crimea, though the legitimacy of the latter is scarcely recognized internationally.

The occupation began during Ukraine's Revolution of Dignity, which ousted pro-Russian president Viktor Yanukovych. Russian special forces without insignia took control of Crimea's government buildings, surrounded Ukrainian military bases, and blockaded the peninsula. A pro-Russian government was installed and a referendum on Crimea's status was held under occupation. According to the Russian-installed authorities, the result was in favour of joining Russia. It annexed Crimea on 18 March 2014, re-organizing it as a Russian republic and turning Sevastopol into a Russian federal city.

Since the beginning of the Russian invasion of mainland Ukraine in February 2022, Russia has used Crimea as a base from which to attack mainland Ukraine. The Ukrainian military has responded with attacks on Russian forces in Crimea. One of Russia's preconditions for ending the invasion has been the recognition of Russian claims to Crimea, while one of Ukraine's goals is to liberate the territory, by military means if necessary.