Ukraine in maps: How the crisis spread
The crisis in Ukraine began in November last year when pro-Moscow President Viktor Yanukovych abandoned a deal with the EU in favour of stronger ties with Russia.
Protests erupted in the capital Kiev and quickly escalated as government buildings were seized in cities across the western regions of Ukraine.Protests in western Ukraine
On 20 February at least 88 people were killed in 48 hours in Kiev.
Videos showed uniformed snipers firing at protesters holding makeshift shields. President Yanukovych signed a ceasefire deal with the opposition but then disappeared and parliament voted to remove him from power.
Ukraine has been torn between east and west since the collapse of the Soviet Union in 1991. While Ukrainian is the main language in western regions, Russian is predominant in parts of the east and south.
The division is also reflected in voting patterns. Mr Yanukovych received most support in the southern and eastern regions of Ukraine in the 2010 election.Protests spread south to Crimea
On 27-28 February pro-Russian gunmen seized key buildings in the Crimean capital, Simferopol.
Within days the parliament voted to join Russia and called a referendum.
The majority of Crimea's 2.3 million population identify themselves as ethnic Russians and speak Russian - a legacy of Russia's 200-year involvement in the region.
Russia's Black Sea Fleet also has its historic base in the Crimean coastal city of Sevastopol.
On 16 March, 97% of voters reportedly backed the proposal to join Russia. That figure was later disputed, with leaked documents showing only 50-60% support for the move.
The EU and US condemned the "annexation" of Crimea and imposed sanctions on Russian and Ukrainian officials.Trouble spreads east
Pro-Russian sentiment is strong in eastern regions such as Donetsk and Luhansk, Ukraine's industrial heartland. After the withdrawal of Ukrainian troops from Crimea, there were reports of large numbers of Russian troops gathering just over the border.
On 7 April protesters occupied government buildings in the eastern cities of Donetsk, Luhansk and Kharkiv.
Although the Kharkiv building was retaken the following day, the occupations spread to other cities, and a number of pro-Russian leaders declared that referendums on granting greater autonomy to eastern regions would be held on 11 May.
On 17 April, the US, EU, Russia and Ukraine reached a deal in Geneva to "de-escalate" the crisis quickly, but the agreement quickly unravelled.
On 25 April eight Organisation for Security and Co-operation in Europe (OSCE) military observers were detained by pro-Russian separatists near Sloviansk, accused of being spies.
They were eventually released after a week in captivity. But violent clashes continued in the city.Dozens die in Odessa
On 2 May the conflict moved to the Black Sea city of Odessa where at least 46 pro-Russian activists were killed when a trade union building they had sought refuge in caught fire.
The trouble in Odessa erupted as, further east, Ukrainian forces began to challenge pro-Russian insurgents more aggressively, in many places winning back territory.Eastern referendum
On 7 May Russian President Vladimir Putin proposed that referendums on independence for eastern regions should be postponed.
However a day later, pro-Russian activists in Donetsk and Luhansk said that they would go ahead with their planned votes, with millions of ballot papers printed.
The interim Ukrainian Government said it would ignore the outcome of any vote, and press ahead with its "anti-terror" operations against the separatists.
The EU said that any vote "could have no democratic legitimacy and would only worsen the situation".Presidential election
Elections for a new president in Ukraine were held on 25 May resulting in confectionary tycoon Petro Poroshenko being elected with over 55% of the vote, although no polling stations were open in Donetsk city and several other locations.
On 20 June President Poroshenko announced a 15-point peace plan and declared a week-long truce. It held for a few days until a military helicopter was shot down over eastern Ukraine.
With a government offensive launched once more, on 5 July rebels abandoned strongholds in the north of Donetsk region, withdrawing to a much-reduced pocket of insurgency in the south.Ukraine's economic ties
Ukraine has economic ties to both the EU and Russia.
It imports most of its gas and oil from Russia - and because energy has been heavily subsidised the country has become overly-reliant on fuel imports.
About one-third of Europe's gas also comes from Russia - about half of it through Ukraine.
Ukraine is heavily in debt. A rescue package agreed with Russia was cancelled after the protesters forced out Mr Yanukovych.
The International Monetary Fund has now approved a $17.1 bn (£10.1 bn) bailout for Ukraine the help the country's struggling economy. With funds from other donors, including the EU, the total package will be worth £32.1bn.
But the loan is dependent on strict economic reforms, including raising taxes and energy prices, which are unlikely to prove popular with voters.