Ukraine crisis timeline
A decision in November 2013 by Ukraine's then President Viktor Yanukovych to pull out of an association deal with the European Union sparked huge street protests that eventually led to his downfall.
In March, Russia reacted by annexing the Ukrainian region of Crimea and unrest began growing in eastern Ukraine, where pro-Russian sentiment is strong. Relations between the West and Moscow have soured dramatically.
5 July: Rebels abandon strongholds in the north of Donetsk region, apparently fleeing south to the regional capital in the face of a government offensive.
27 June: The EU signs an association agreement with Ukraine, along with Georgia and Moldova, in what President Petro Poroshenko describes as the most important day in the country's history since independence in 1991.
25 June: Russia's parliament cancels a parliamentary resolution authorising the use of Russian forces in Ukraine. EU leaders welcome the move but warn of more sanctions if Russia does not do more to de-escalate tensions in Ukraine.
24 June: A Ukrainian military helicopter is shot down in the east, killing nine people, as the UN estimates more than 420 people were killed in eastern Ukraine between April 15 and June 20.
23 June: Rebels agree to observe the ceasefire proposed by the government until 27 June, but say they will not disarm until government troops leave the east.
21 June: The US imposes sanctions against seven pro-Russian leaders in Ukraine.
20 June: President Poroshenko announces a 15-point peace plan and declares a week-long truce.
17 June: Russian state TV journalist Igor Kornelyuk is killed in a mortar attack near a village outside the eastern Ukrainian city of Luhansk.
16 June: Russia cuts off all gas supplies to Ukraine, as Gazprom says Ukraine has failed to settle its debts.
14 June: A violent protest outside the Russian embassy in Ukraine leads to windows being smashed and cars being overturned. Meanwhile, pro-Russia separatists shoot down a military plane in the east, killing 49 people.
13 June: Government troops win back the port city of Mariupol from pro-Russian separatist rebels after heavy fighting.
12 June: Ukraine says three Russian tanks have entered rebel areas in the east. Russia denies the allegations.
10 June: Petro Poroshenko orders the creation of humanitarian corridors so civilians can flee areas of east Ukraine hit by conflict.
7 June: Petro Poroshenko is sworn in as president of Ukraine, amid hopes the move could help put an end to deadly fighting in the east of the country.
6 June: Russian President Vladimir Putin and Ukrainian President-elect Petro Poroshenko call for a quick end to the bloodshed in eastern Ukraine
5 June: Leaders of the G7 industrial nations urge Russia to begin talks with the new leadership in Kiev to end the crisis in eastern Ukraine.
4 June: Separatist rebels take two Ukrainian military bases in the eastern region of Luhansk as fighting continues near the rebel-held town of Sloviansk.
4 June: US President Barack Obama condemns Russian "aggression" in Ukraine while speaking in Warsaw to mark 25 years since the fall of communism in Poland.
3 June: Nato pledges to bolster its defence capabilities in response to Russian actions in Ukraine, but says it will stick to a key agreement with Moscow.
30 May: Ukrainian forces will continue their offensive against rebels until peace and order are restored in the east, interim Defence Minister Mykhailo Koval says.
29 May: Pro-Russian rebels shoot down a military helicopter near Sloviansk, killing 14 people including a general.
26 May: Russia says it is "open to dialogue" with President-elect Petro Poroshenko but insists military action against separatists must stop.
26-27 May: Ukrainian army launches "anti-terrorist operation" to oust separatists occupying Donetsk airport. Combat jets, helicopters and airborne troops deployed and at least 40 separatists killed.
25 May: Ukraine holds presidential election but most polling stations in east remain closed. President-elect Petro Poroshenko vows to bring "peace to a united and free Ukraine".
22 May: Rebel attack on checkpoint in Volnovakha, east Ukraine, leaves 14 soldiers dead.
19 May: Russia's President Vladimir Putin says he has ordered troops near Ukraine's border to withdraw, but Nato says there is no sign they have pulled back.
11 May: Pro-Russian separatists in Donetsk and Luhansk declare independence after referendums which were not recognised by Kiev or the West.
7 May: In an apparent shift in Russian policy, President Putin calls for referendums in eastern Ukraine to be postponed to encourage dialogue. He also describes Ukraine's presidential elections scheduled for 25 May as a move "in the right direction".
4 May: Pro-Russian protesters attack the police headquarters in Odessa, prompting police to release dozens of people arrested over the earlier unrest. Interim PM Arseniy Yatsenyuk says "inefficient" police failed to prevent the fire two days earlier.
3 May: Seven international military observers held for a week by pro-Russian gunmen in eastern Sloviansk are released..
2 May: Acting President Olexander Turchynov says many pro-Russia rebels have been killed, injured and arrested in a government offensive in the eastern city of Sloviansk. Pro-Russians shoot down two Ukrainian military helicopters, killing a pilot and another serviceman. Clashes in the Black Sea city of Odessa leave at least 42 people dead, most of them pro-Russian activists killed when a building they had barricaded themselves inside caught fire. .
1 May: Acting President Olexander Turchynov reinstates conscription, warning Ukraine is on "full combat alert". Pro-Russians take over the regional prosecutor's office in eastern Donetsk.
25 April: Eight OSCE international military observers are detained by pro-Russian separatists near Sloviansk, accused of being spies.
23 April: Tony Blair warns Western leaders they must put aside their differences with Russia over Ukraine to focus on the threat of Islamic extremism.
22 April: Ukraine's acting president orders the relaunch of military operations against pro-Russian militants in the east after two men, one a local politician, are found "tortured to death" in Donetsk region.
20 April: The shooting of three people manning a pro-Russian checkpoint near Sloviansk outrages Russia, which blames it on Ukrainian nationalists.
19 April: The appearance of threatening anti-Semitic leaflets in Donetsk spreads alarm among Jews though pro-Russian forces dismiss them as a hoax to discredit them.
17 April: Russia, Ukraine, the US and the EU say they have agreed at talks in Geneva on steps to "de-escalate" the crisis in eastern Ukraine. Three people are killed when Ukrainian security forces fend off a raid on a base in Mariupol. In Moscow, Russian President Vladimir Putin warns Ukraine is heading into an "abyss" by confronting pro-Russian separatists in the east of the country. He also dismisses claims that Russian agents are acting in eastern Ukraine.
16 April: "Anti-terrorist" operation quickly stalls: pro-Russian militants in eastern Ukraine seize six armoured vehicles after they are blockaded by civilians and gunmen in the town of Kramatorsk. There is also an angry confrontation between civilians and soldiers in a village nearby.
15 April: Ukraine's acting President, Olexander Turchynov, announces the start of an "anti-terrorist operation" against pro-Russian separatists.
12 April: In eastern Ukraine, occupations of official buildings by pro-Russian protesters and militants multiply.
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. Ukrainian 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 has ordered a "partial withdrawal" of troops from the border with Ukraine, the German government announces.
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 Olexander 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 was killed as a military base was 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 officers, 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 the winner in a 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.