Crimea returned to Russia after a referendum on the peninsula.
… the sanctions imposed on Russia as a result of the Ukrainian crisis and the return of Crimea to Russia…
The return of Crimea in 2014, was a result of an acute political crisis in Ukraine, which came in response to the will expressed by the overwhelming majority of its population in a popular referendum, in full accordance with international law.
Recurring pro-Kremlin disinformation narrative about the illegal annexation of Crimea.
Crimea is a part of Ukraine and was illegally annexed by Russia. In 2014, Russian troops obliged the parliament of Crimea to organise a referendum, which was illegitimate under international law, and then formally annexed the peninsula and brought it under Russian territorial control.
No international body recognises the so-called referendum, announced on 27 February 2014 and held on 16 March 2014.
A year after the illegal “return”, Russian President Vladimir Putin admitted that the plan to annex Crimea was ordered weeks before the so-called referendum.
Sanctions were first introduced in June 2014 in response to the attempts to deliberately undermine Ukraine’s territorial integrity and destabilise the country. Other EU measures in place in response to the crisis in Ukraine include economic sanctions targeting specific sectors of the Russian economy and individual restrictive measures. For the EU's statement on the sixth anniversary of Crimea annexation see here.