Russia-Ukraine Dispute over Crimea: Key dates and events
March 16: Crimean residents, mostly Russian speakers, vote to join Russia. The referendum is not recognised by Kiev and the West.
March 20: Russia's parliament ratifies a treaty incorporating Crimea into Russia. The move is condemned abroad as an annexation, sparking the worst diplomatic crisis between Russia and the West since the Cold War.
April 6: Pro-Moscow demonstrators seize government buildings in eastern Ukraine, including Donetsk and Lugansk.
April 13: Kiev announces launch of "anti-terrorist" operation to reclaim eastern areas controlled by the separatists.
May 11: Voters back independence in referendums in Lugansk and Donetsk, rejected as illegitimate by Kiev and the West.
July 17: Malaysia Airlines flight MH17 is shot down, apparently by a missile, over rebel-held territory, killing 298 people. Kiev and the rebels blame each other.
August 25: Rebels mount a counter-offensive in the southeast, reportedly backed by Russian troops and heavy weapons, and inflicting a series of defeats on Ukrainian troops.
September 5: Ceasefire signed in the Belarus capital Minsk between Kiev and the rebels, with the participation of Russia and the Organisation for Security and Cooperation in Europe (OSCE). In mid-October, new negotiations fail and violence resumes.
October 26: Pro-Western parties win big in a general election boycotted in the east. On November 2 separatists win leadership elections in the east that Kiev and the West refuse to recognise.
January 22, 2015: Donetsk airport, in ruins after nine months of fighting, falls completely to the rebels.
February 12: Ukraine government and rebels agree to a "Minsk II" peace roadmap, backed by France, Germany and Russia.
The ceasefire deal strengthens the provisions of the Minsk I agreement, enlarging the buffer zone from which heavy weapons should be withdrawn.
August 31: As lawmakers give initial backing to reforms - demanded by Kiev's western allies -- granting more autonomy to pro-Russian separatists, fierce clashes erupt between police and nationalist demonstrators outside the Ukrainian parliament.
Tensions in eastern Ukraine fall thanks to the Minsk deal, but the truce remains fragile and is tested an almost daily basis by deadly incidents. The fighting has left more than 9,500 dead since April, 2014.
August 10: Russia's security service says it has thwarted "terrorist attacks" in Crimea by Ukrainian military intelligence and beaten back an armed assault by Kiev's forces. Ukrainian President Petro Poroshenko denies the charges.
August 11: Ukraine places its forces around Crimea on high alert while Russian President Vladimir Putin meets with security chiefs to discussing "additional measures" for security in the peninsula.