Attention centered on Ukraine's southern Crimea region when pro-Russia gunmen seized control of key government buildings in the regional capital Simferopol. Crimea is the base of Russia's Black Sea fleet and has deep ties with Russia.
Russia maintains its Black Sea fleet at Sevastopol in Crimea, Ukraine. Under earlier agreements with Ukraine, Russia is allowed to keep several thousands troops in Crimea. This graphic also compares Russia and Ukraine's over all military forces.
Ukraine lies between the European Union and Russia, and has ties to both. Pipelines carry Russian gas through Ukraine to the EU. Ukraine's suspension of an association agreement with the EU fueled the current unrest in Ukraine.
Russian is widely spoken in the southern and eastern parts of Ukraine, including in Crimea.
Ukraine's 2010 presidential election results show a divide between the largely Ukrainian speaking west and largely Russian speaking east of the country. Viktor Yanukovych was declared the winner of the election, with 48.95% of the vote, compared to 45.47% for Yulia Tymoshenko.
Gas travels into Ukraine from Russia and Belarus before being moved westward to Poland, Slovakia, Hungary and Romania.
Massive protests erupted in Kyiv in November, 2013. Anti-government protesters set up camps in Independence Square and seized control of government buildings. Some protests turned into violent clashes with police and counter-protesters.