Ukraine votes overwhelmingly for independence from the crumbling Soviet Union in a referendum on December 1, 1991. Russian President Boris Yeltsin recognises it the next day and a week later Russia, Ukraine and Belarus sign an accord establishing the Community of Independent States (CIS).
After the USSR finally collapses on December 25, 1991, Ukraine spends the next five years trying to wriggle free of its giant neighbour which has dominated it for three centuries.
Kyiv is lukewarm about the CIS, regarding it as a Russian ploy to bring former Soviet republics back into its orbit.
Moscow, Washington and London sign an accord in Budapest on December 5, 1994 to respect Ukraine's independence, its sovereignty and its borders.
Friendship treaty with Moscow
Russia and Ukraine sign a friendship and cooperation treaty in 1997 but it fails to lift all the ambiguity which overshadows their relations.
The treaty resolves a thorny dispute over the share out of the ex-Soviet Black Sea fleet which is anchored in Sevastopol in Crimea.
Russia remains owner of most of the ships, but agrees to pay Ukraine rent to use the port of Sevastopol.
The Kremlin is deeply opposed to Ukraine or any other ex-Soviet republic joining NATO and it is able to hold an economic gun to Ukraine's head.
Russia remains Ukraine's most important trading partner, and Kyiv is totally dependent on Russian oil and gas.
Pro-Westerner survives poisoning
In 2004, Ukraine's fraud tainted presidential election is won by Russia-backed candidate Viktor Yanukovych. But after unprecedented street protests, the election is annulled.
The victory on December 26 of pro-Western opposition leader Viktor Yushchenko marks the beginning of a new political era in Ukraine after a decade under the thumb of Moscow-oriented Leonid Kuchma.
Yushchenko is victim of a mysterious dioxin attack, which disfigures him, during the campaign but survives.
From his arrival in power, Yushchenko voices Ukraine's wish to join the EU, despite opposition from Brussels and NATO.
But in 2008 NATO provokes Moscow's ire when its leaders declare that Ukraine might one day join the alliance.
The two neighbours go through several trade wars and stand-offs, the most spectacular being over gas in 2006 and 2009 which disrupts Europe's energy supplies.
President Viktor Yanukovych comes to power in February 2010 and begins a rapid rapprochement with Russia, while saying integration with the EU remains a priority.
But under pressure from the Kremlin, he refuses at the last minute to sign an accord with the EU in November and instead goes for a trade deal with Moscow.
The U-turn unleashes a mass pro-European protest movement centred on Kiev's central square, the Maidan.
The street revolt ends in February 2014 with Yanukovych's flight to Russia and his impeachment, after the deaths of around a hundred protesters in violent clashes.
Crimea then Donbas
Russia riposts by deploying its "polite little green men" in Crimea, which turn out to be Russian troops, and then annexing the peninsula.
On March 16, 2014 a Moscow-run referendum there approves the Russia takeover.
The annexation provokes the worst diplomatic crisis between the West and Russia since the fall of the Soviet Union and heavy sanctions are imposed on Moscow.
Then in April, pro-Russian separatists seize key sites in Donbas, a mostly Russian-speaking industrial region in eastern Ukraine. Clashes degenerate into war in May.
Kyiv and the West believe that Moscow has engineered the separatist drive in retaliation for Ukraine's pro-Western slant.
Some 14,000 people die in the conflict.
Build-up then invasion
Since late 2021 Moscow has massed tens of thousands of soldiers on Ukraine's borders, fuelling fears of an invasion.
On Monday, Russian President Vladimir Putin recognises the independence of the two separatist self-proclaimed republics of Donetsk and Lugansk.
Three days later Russian forces invade Ukraine with Putin warning the West of "horrible consequences" if it interferes.