Nov. 21, 2013: Protesters take to the streets after Ukrainian President Viktor Yanukovych says it will abandon an agreement on closer ties with Europe in favour of tighter links with Moscow. Demonstrations grow bloodier over the weeks.
Feb. 22, 2014: Parliament votes to dismiss Yanukovych.
Feb. 23, 2014: Pro-Russia protesters start rallying in Crimea, where Russia has a major naval base.
Feb. 28, 2014: Baird travels to Ukraine for talks with the new government.
March 1, 2014: Troops under apparent Russian command take over Crimea without firing a shot.
March 6, 2014: Harper calls Russia’s invasion of Ukraine an act of aggression and a clear violation of Ukraine’s sovereignty and of international law.
March 13, 2014: Harper announces more than $220 million in support to help Ukraine stabilize its economy and promote economic and social development.
March 16, 2014: Official results from a secession referendum in Crimea say 97 per cent of voters back a proposal to join Russia. Canada and other allies reject the results.
March 22, 2014: Harper makes a whirlwind visit to Kyiv to show support.
April 14, 2014: Then-foreign minister John Baird says he will visit eastern Europe to pledge support against what he says are Russian moves to destabilize the region. Baird visits the Czech Republic, Slovakia, Poland, Latvia and Estonia over four days.
April 28, 2014: Defence Minister Ron Nicholson says six CF-18 fighter aircraft will fly to Romania as part of NATO efforts to reassure allies in central and eastern Europe.
June 7, 2014: Harper flies to Kyiv for Poroshenko's swearing-in as president.
Sept. 17, 2014: Ukrainian President Petro Poroshenko visits Ottawa and addresses a joint session of Parliament.
Nov. 15, 2014: Prime Minister Stephen Harper tells Russian President Vladimir Putin to "get out of Ukraine" when the two met at a Group of 20 summit of major economies in Australia.
April 14, 2015: Harper and Defence Minister Jason Kenney announce plans for Canada to send 200 military trainers to Ukraine, joining the U.S. and Britain in an effort to shore up the country's combat forces.