Political context to Ukrainian conflict:

This map illustrates very effectively the political divide that was present in Ukraine prior to the recent conflict. The Blue parts of the map indicate where the majority vote was with Yanukovych, a pro-Russian leader of state, who was the most recent elected president of Ukraine. The yellow indicates majority support for Tymoshenko, who was a more progressive leader. 

Note also the almost perfect geographical consistency of votes, with the East of Ukraine, the side closer to Russia, is majority Yanukovych, while the West, closer to Europe, is majority Tymoshenko.