Ukraine gained independence after the collapse of the Soviet Union in 1991 and has since veered between seeking closer integration with Western Europe and being drawn into the orbit of Russia, which sees its interests as threatened by a Western-leaning Ukraine.
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 closer ties with its European neighbours, particularly Poland, and nationalist sentiment is strongest there.
A significant minority of the population uses Russian as its first language, particularly in the cities and the industrialised east.
An uprising against pro-Russian President Viktor Yanukovych in 2014 ushered in a Western-leaning government, but Russia used the opportunity to seize the Crimean peninsula and arm insurgent groups to occupy parts of the industrialised east of Ukraine.
President: Volodymyr Zelensky
Mr Zelensky's initial claim to fame was playing a fictional president in a television comedy programme, and his victorious election campaign emphasised content-light social media videos over traditional rallies and policy speeches.
His message was, like that of his TV character, pitched against corruption and the power of oligarchs, but Mr Zelensky himself has close ties to Ihor Kolomoisky, who owns the 1+1 channel that his show appears on.
Mr Kolomoisky, who fell out with the then President Petro Poroshenko in 2015, has been living abroad because of numerous investigations into his business dealings at home, and gave the incoming president strong support during the election campaign.
In his inaugural address, President Zelensky said ending the Russian-backed insurgency in the east of the country would be his priority.
His Servant of the People party went on to win early parliamentary elections in July, giving President Zelensky control of both the executive and the legislature.
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National media have adopted a united patriotic agenda following the Russian annexation of Crimea and the armed conflict in the east.
Ukraine has banned relays of leading Russian TVs; in turn, areas under Russian or separatist control have seen pro-Kyiv outlets silenced.
The authorities also block access to some popular Russian websites and social networks.
TV dominates the media landscape, and major commercial networks are the leading outlets.
Many newspapers publish Ukrainian and Russian-language editions.
Some key dates in Ukraine's history:
1918 - Ukraine declares independence after Russian Revolution.
1921 - Soviet rule established as Russian Red Army conquers two-thirds of Ukraine.
1932 - At least seven million peasants perish in man-made famine during Stalin's collectivisation campaign.
1941-44 - Ukraine suffers terrible wartime devastation during Nazis occupation.
1945 - Allied victory in Second World War leads to conclusive Soviet annexation of west Ukrainian lands.
1986 - A reactor at the Chernobyl nuclear power station explodes, sending a radioactive plume across Europe.
1991 - As the Soviet Union heads towards dissolution, Ukraine declares independence.
2004 - Orange Revolution mass protests force pro-European change of government.
2014 February - Maidan Revolution ousts pro-Kremlin government over stalled European Union association deal. Russia subsequently seizes Crimean peninsula and launches insurgency to occupy parts of eastern Ukraine.
2019 April - Volodymyr Zelensky, a comedian and actor with no previous experience in politics, wins presidential election run-off in a landslide victory.