Revolution November 2013, was when Ukraine's President Viktor Yanukoych rejected a trade deal with the European Union taking a bail out from Russia instead. Thousands of people young and old began protesting the move a Kiev's square because they saw the EU deal as key to the country's economic future. The government cracked down hard leading to the deaths of atleast 70 Ukrainians by Feburary 2014. Ukraine's politicans eventually removed Yanukoych from power and paved the way for a new presidential election. Petro Poroshenko who supported the protests was voted into office and that's where the crisis might have ended if it weren't for two things. One, Ukraine is divided between an eastern region with historic and cultural ties to Russia and the rest of the country which identifies as more Ukrainian than anything else. Two, Russia does not want to lose it's influence in Ukraine which takes us to Crimea, a battleground in the Ukraine-Russia conflict.
Rebellion A rebellion fueled by Pro-Russian separatists and other parts of Eastern Ukraine. Rebels took control of government buildings in several eastern cities in April and while they started out as disorganized group, Russian nationals with experience were sent across the border to meet them according to the United Nations. Meanwhile, Ukraine's own forces fought back for control. Atleast 1,000 people died between Mid-April and Mid-July because of the conflict, many of them civilians and around 300 people died when Malaysia Airlines flight 17 was apparently mistakenly shot down by rebels triggering more EU sanctions on Russia. Russia for it's part denied sending troops and weapons over the border despite Ukrain's claims, NATO photos and even video footage to the contrary.
Annexation Crimea happens to sit on an oil and gas bonanza. Most Crimean speak Russian as their native language as do many people in eastern Ukraine and when the pro European Union protests were winding down in Kiev pro-Russian protestors began making their voices heard in Crimea. Russian soldiers and unmarked uniforms then took over buildings and airports in the region. Russia would eventually send hundreds of troops into Crimea which Ukraine called an invasion, but Crimean politicians put separtation from Ukraine up for a vote. More than three quarters Crimeans voted to become part of Russia. Russian President Vladimir Putin annouced that Crimea was now part of Russia. The international community was not having it. NATO codemned what it called the so-called referendum held at gunpoint. The EU and USA slapped Russia with what would be just the first round of sanctions.