From the CBC, 19 February 2014:
The anti-government demonstrations that have gripped Ukraine for nearly three months have been steered by divergent protest movements. The demonstrations began when President Viktor Yanukovych reneged on a plan to form a trade alliance with the European Union, saying it would jeopardize the country’s trading bonds with Russia.
Some protest groups are seeking to force Yanukovych to agree to the EU trade deal while other nationalist parties are calling for greater independence free from foreign influence. Here are the key players in the political crisis that continues to unfold.
See also: NY Times, How It All Began: a Cold War Battle Heats Up