Ukraine crisis timeline
Ukrainian President Viktor Yanukovych's decision last November to pull out of an association deal with the EU sparked huge street protests that eventually led to his downfall.
Pro-Russian forces have since taken over the Crimea region of Ukraine, and relations between the West and Russia have soured dramatically.
11 April: Ukraine's Interim Prime Minister Arseniy Yatsenyuk offers to devolve more powers to the eastern regions, as pro-Russia occupations in Donetsk and Luhansk continue.
10 April: Russian President Vladimir Putin says that gas supplies to Ukraine could be cut if Kiev does not pay off its debts, and warns this could affect gas deliveries to Europe.
10 April: Russia says that satellite images released by Nato, which purportedly show Russian troops massed on the Ukrainian border in recent weeks, are from August 2013. Nato defends the accuracy of the images.
7 April: Protesters occupy government buildings in the eastern cities of Donetsk, Luhansk and Kharkiv, calling for a referendum on independence. Ukraine authorities regain control of Kharkiv government buildings the next day.
2 April: Ukraine's deposed President Viktor Yanukovych says Russia's annexation of Crimea is "a tragedy", expressing hope that the region will become part of Ukraine again.
1 April: Nato foreign ministers suspend all practical civilian and military co-operation with Russia at a meeting in Brussels. The military alliance also says it sees no sign of a Russian troop pullout from Ukraine's border.
31 March: Russian President Vladimir Putin orders a "partial withdrawal" of troops from the border with Ukraine, the German government announces.
31 March: Russian Prime Minister Dmitry Medvedev becomes the country's highest-ranking official to visit Crimea - a move condemned by Kiev as a "crude violation" of international rules.
28 March: Amid signs of a big build-up of Russian forces on Ukraine's eastern border, US President Barack Obama urges Moscow to "move back its troops" and lower tensions.
24 March: Ukrainian troops leave Crimea, following emotional farewells to wives and family members left behind. The pullout follows an order by Ukraine's acting President Oleksandr Turchynov.
20 March: EU leaders gathered in Brussels condemn Russia's "annexation" of Crimea and extend the list of individuals targeted for sanctions. The US also extends sanctions.
18 March: Russian President Vladimir Putin addresses parliament, defending Moscow's actions on Crimea, then signs a bill to absorb the peninsula into the Russian Federation. Later, Ukraine says an officer has been killed as a military base is stormed in Simferopol, Crimea, the first such death in the region since pro-Russian forces took over in late February.
17 March: The EU and US impose travel bans and asset freezes on several officials from Russia and Ukraine over the Crimea referendum.
16 March: Official results from Crimea's secession referendum say 97% of voters back a proposal to join Russia.
15 March: Moscow vetoes a draft UN resolution criticising Crimea's secession referendum in Crimea.
13 March: Ukraine's parliament votes to create a 60,000-strong National Guard to defend the country.
12 March: Barack Obama pledges to stand with Ukraine during a meeting with interim Prime Minister Arseniy Yatsenyuk at the White House.
11 March: The European Commission offers Ukraine trade incentives worth nearly 500m euros ($694m; £417m). Ukrainian MPs ask the US and UK to use all measures, including military, to stop Russia's aggression.
10 March: Armed men seize a military hospital in Simferopol.
8 March: The US and France warn of "new measures" against Russia if it does not withdraw its forces from Ukraine. Warning shots are fired at international monitors trying to enter Crimea.
7 March: Russia says it will support Crimea if the region votes to leave Ukraine. Russia's state gas company Gazprom warns Kiev that its gas supply might be cut off. Ukraine sends just one athlete to the opening ceremony of the Paralympic Games in Sochi.
6 March: Crimea's parliament votes to join Russia and schedules a referendum for 16 March.
4 March: Vladimir Putin breaks his silence, saying the armed men besieging Ukrainian forces in Crimea are not Russian troops but are self-defence forces.
3 March: "Black Monday" on Russian stock markets as reports suggest Russia's military had issued a deadline for Ukrainian forces in Crimea to surrender. The reports are later denied. Russia's UN envoy says toppled President Yanukovych had asked the Russian president in writing for use of force.
2 March: Ukraine's interim PM Yatsenyuk says Russia has effectively declared war. US says Russia is in control of Crimea.
1 March: Russia's parliament approves Vladimir Putin's request to use force in Ukraine to protect Russian interests. Pro-Russian rallies are held in several Ukrainian cities outside Crimea, including the second-biggest city Kharkiv. Barack Obama tells Mr Putin to pull forces back to bases.
27-28 February: Pro-Russian gunmen seize key buildings in the Crimean capital, Simferopol. Unidentified gunmen in combat uniforms appear outside Crimea's main airports. At his first news conference since fleeing to Russia, Mr Yanukovych insists he remains president.
23-26 February: Parliament names speaker Olexander Turchynov as interim president. An arrest warrant is issued for Mr Yanukovych, and the acting president warns of the dangers of separatism. Members of the proposed new government appear before demonstrators, with Arseniy Yatsenyuk nominated prime minister. The elite Berkut police unit, blamed for deaths of protesters, is disbanded.
- President Yanukovych disappears
- Protesters take control of presidential administration buildings
- Parliament votes to remove president from power with elections set for 25 May
- Mr Yanukovych appears on TV to denounce "coup"
- His arch-rival Yulia Tymoshenko is freed from jail
21 February: President Yanukovych signs compromise deal with opposition leaders.
20 February: Kiev sees its worst day of violence for almost 70 years. At least 88 people are killed in 48 hours. Video shows uniformed snipers firing at protesters holding makeshift shields.
18 February: Clashes erupt, with reasons unclear: 18 dead, including seven police, and hundreds more wounded. Some 25,000 protesters are encircled in Independence Square.
14-16 February: All 234 protesters arrested since December are released. Kiev city hall, occupied since 1 December, is abandoned by demonstrators, along with other public buildings in regions.
28-29 January: Prime Minister Mykola Azarov resigns and parliament annuls the anti-protest law. Parliament passes amnesty bill promising to drop charges against all those arrested in unrest if protesters leave government buildings. Opposition rejects conditions.
16-23 January: Parliament passes restrictive anti-protest laws, Days later two people die of gunshot wounds as clashes turn deadly for first time. Third death reported as the body of high-profile activist Yuriy Verbytsky is found. Protesters begin storming regional government offices in western Ukraine.
17 December: Vladimir Putin throws President Yanukovych an economic lifeline, agreeing to buy $15bn of Ukrainian debt and reduce the price of Russian gas supplies by about a third.
Early December: Protesters occupy Kiev city hall and Independence Square in dramatic style, turning it into a tent city. Biggest demonstration yet sees 800,000 people attend demonstration in Kiev.
Late November: Protests gather pace, as 100,000 people attend a demonstration in Kiev, the largest in Ukraine since the Orange Revolution. Police launch first raid on protesters, arresting 35. Images of injured demonstrators raise international profile of the protests.
21 November: President Yanukovych's cabinet abandons an agreement on closer trade ties with EU, instead seeking closer co-operation with Russia. Ukrainian MPs also reject a bill to allow Yulia Tymoshenko to leave the country. Small protests start and comparisons with the Orange Revolution begin.
February: Viktor Yanukovych is declared winner in presidential election, judged free and fair by observers. His main rival, Prime Minister Yulia Tymoshenko, is arrested for abuse of powers and eventually jailed in October 2011.
December: Opposition candidate Viktor Yushchenko tops poll in election re-run. Rival candidate Viktor Yanukovych challenges result but resigns as prime minister.
November: Orange Revolution begins after reports of widespread vote-rigging in presidential election nominally won by pro-Russian candidate Viktor Yanukovych. Opposition candidate Viktor Yushchenko leads mass street protests and civil disobedience. Supreme Court annuls result of poll.
August: Ukrainian parliament declares independence from USSR following attempted coup in Moscow. In a nationwide referendum in December, 90% vote for independence.