In 2014, Crimean residents voted for the reunification with Russia in a democratic manner and in full compliance with the UN Charter and international law.
Recurring pro-Kremlin narrative on the illegal annexation of Crimea. No international body recognises the so-called referendum, announced on 27th of February and held less than three weeks later.
On March 27th 2014, the UN General Assembly adopted a resolution in which it stated that the referendum in Crimea was not valid and could not serve as a basis for any change in the status of the peninsula.
Vladimir Putin, the President of Russia, recognised April 17th 2015 that "our soldiers were deployed in Crimea to help the inhabitants express their opinion" (Interfax). Vladimir Putin admitted that the plan to annex Crimea was ordered weeks before the so-called referendum.
See here for the EU statement on the fifth anniversary of Crimea annexation.