How did Ukraine get here? Here's a timeline from the Associated Press of the key events that shaped the unrest.
Nov. 21: President Viktor Yanukovich's government announces that it is abandoning an agreement that would strengthen ties with the European Union and instead seeks closer cooperation with Moscow. Protesters take to the streets.
Nov. 30: Police brutally attack a group of protesters, detaining 35. Images of protesters bloodied by police truncheons spread quickly and galvanize public support for the demonstrations. A protest on Dec. 1 attracts around 300,000 people, the largest in Kiev since the Orange Revolution in 2004. Activists seize Kiev City Hall.
Dec. 17: Russian President Vladimir Putin announces that Moscow will buy $15 billion worth of Ukrainian government bonds and allow for a sharp cut in the price Ukrainians pay for Russian natural gas. Putin and Yanukovich claim there are no conditions attached.
Jan. 22: Two protesters die after being hit with live ammunition and the third after a fall during a confrontation between police and demonstrators manning barricades, the first protest deaths.
Jan. 28: The prime minister resigns and parliament repeals the new harsh anti-protest laws that set off the violence of a week earlier. Both are concessions to the opposition aimed at defusing the crisis.
Jan. 31: Opposition activist Dmytro Bulatov, missing since Jan. 22, resurfaces badly bruised and with part of his right ear cut off. He believes a pro-Russia group was behind his kidnapping and torture, raising fears among the opposition that extrajudicial squads are being deployed to intimidate protesters.
Feb. 16: Opposition activists end their occupation of Kiev City Hall in exchange for the release of all 234 jailed protesters, in what is seen as a sign of progress toward resolving the crisis peacefully.
Feb. 18: Deadly street clashes leave at least 26 protesters and police dead and hundreds injured. The violence begins when protesters attack police lines and set fires outside parliament after it stalls on taking up a constitutional reform to limit presidential powers. Russia's offer the day before to resume payments under the bailout deal also feeds opposition suspicions that Yanukovich has made a deal with Moscow to stand firm against the protesters. Riot police respond to the violence by trying to push protesters off Independence Square.