Crimean peninsula,which is one of the main key elements in Ukrain’s crisis, is pro-Russian area. Crimea hosts Russian fleet on the Black Sea as well.
This part of Ukraine is smaller than Belgium.
Crimea is the country’s only formally autonomous region. Simferopol is the region’s capital, whereas Sevastopol is a separate town within the country.
Crimea, historically being the part of Russian empire, Russia and later, Soviet Union, became the part of Ukraine only after the USSR collapsed. It actually happened earlier, in 1954, when Nikita Khrushchev gave this peninsula to its native land.
But it was not so important until 1991.Till now, 60% of Crimea’s population can identify themselves as Russian people.
That shows that people are connected with Russia a lot.