Timeline of the Russian annexation of Crimea
The Russian annexation of Crimea took place in the aftermath of the 2014 Ukrainian Revolution of Dignity. On 22–23 February, Russian President Vladimir Putin convened an all-night meeting with security services chiefs to discuss pullout of deposed President, Viktor Yanukovych, and at the end of that meeting Putin remarked that "we must start working on returning Crimea to Russia.".
Source: Wikipedia — Timeline of the Russian annexation of Crimea (CC BY-SA 4.0)