Ukraine gained independence after the collapse of the Soviet Union in 1991 and has since veered between seeking closer integration with Western Europe and reconciliation with Russia, which supplies most of the country's energy.
Europe's second largest country, Ukraine is a land of wide, fertile agricultural plains, with large pockets of heavy industry in the east.
While Ukraine and Russia share common historical origins, the west of the country has close ties with its European neighbours, particularly Poland, and Ukrainian nationalist sentiment is strongest there.
A significant minority of the population of Ukraine are Russians or use Russian as their first language. Russian influence is particularly strong in the industrialised east, as well as in Crimea, an autonomous republic on the Black Sea which was part of Russia until 1954. The Russian Black Sea Fleet is based there.
At a glance
- Politics: Viktor Yanukovych won the 2010 presidential poll, capitalising on voter discontent over economic woes
- Economy: Dependence on steel exports makes Ukraine vulnerable to global financial turmoil. Ukraine received a multibillion-dollar loan from the IMF in 2008 but a further loan approved in 2010 was subsequently frozen
- International: Ukraine faces the challenge of forging closer ties with the EU without incurring the displeasure of Russia, on which it is heavily dependent for energy supplies
Country profiles compiled by BBC Monitoring
Crimea is also the homeland of the Crimean Tatars, whom Stalin accused of collaborating with the Nazis and deported to Central Asia in 1944. More than 250,000 have returned since the late 1980s.
In 1932-1933, Stalin's programme of enforced agricultural collectivisation brought famine and death to millions in Ukraine, the bread basket of the USSR. Not until its twilight years did the Soviet Union acknowledge the extent of the suffering.
News of another Soviet-era calamity, the 1986 accident at the Chernobyl nuclear power station, rang alarm bells around the world immediately. About 8% of Ukraine's territory was contaminated as were large areas in neighbouring Belarus. Millions have suffered as a result.Independence
The first president after independence, former Communist Party official Leonid Kravchuk, presided over rapid economic decline and runaway inflation. His successor, Leonid Kuchma, oversaw a steady economic recovery, but was accused of conceding too much to Russian economic interests.
Opposition to Mr Kuchma grew, further fed by discontent at controls on media freedom, manipulation of the political system and cronyism.
The authorities' attempt to rig the 2004 presidential elections led to the "Orange Revolution", with reference to the colour of the main opposition movement.Orange Revolution
Mass protests, a revolt by state media against government controls and the fracturing of the governing coalition brought in European-Union mediation and a re-run of the election.
A fragile alliance of anti-Kuchma forces united behind pro-Western opposition leader and former Prime Minister Viktor Yushchenko, who won the presidency.
Mr Yushchenko succeeded in carrying out some democratic reform, but moves towards Nato and EU membership were slowed by divided public opinion in Ukraine and Western reluctance to antagonise a resurgent Russia.
Rivalry with his prime minister, Yulia Tymoshenko, soured into open antagonism, and neither proved able to cope with the worldwide economic downturn after 2008.
Their opponent in the Orange Revolution, Viktor Yanukovych, won the 2010 presidential election. He swiftly re-oriented foreign and trade policy towards Russia, clamped down on media freedom, and had various opponents, most prominently Ms Tymoshenko, imprisoned in trials seen at by many as politically-motivated.
Although trade with EU countries now exceeds that with Russia, Moscow is the largest individual trading partner. Ukraine depends on Russia for its gas supplies and forms an important part of the pipeline transit route for Russian gas exports to Europe.
In 2006, Ukraine was forced to agree to pay almost twice the former price for Russian gas after Russia briefly to cut supplies in a move that sparked alarm in western Europe as well. In January 2009, Russia again cut gas supplies in a row over unpaid fees.
The Ukrainian economy's dependence on steel exports made it particularly vulnerable to the effects of the global financial crisis of 2008, and in October of that year the country was offered a $16.5bn (£10.4bn) loan by the International Monetary Fund (IMF). A further IMF bailout of $15bn (£9bn) was approved in 2010 but frozen the following year after the government failed to implement the financial reforms required as a condition of the loan.
Recent moves to reach an association agreement with the EU - seen as a key step towards eventual EU membership - again fuelled tensions with Russia, and the government's decision to drop the agreement brought tens of thousands of protesters out onto the streets in November 2013.