Britain was the world's first industrialised country. Its economy remains one of the largest, but it has for many years been based on service industries rather than on manufacturing.
Despite being a major member of the EU, the country is not part of the eurozone. The prospect of its joining receded still further after the UK blocked proposed changes to the EU's Lisbon Treaty aimed at addressing the crisis in the eurozone, which by the autumn of 2011 had reached an acute phase.
In recent years the UK has taken steps to devolve powers to Scotland and Wales. The Scottish Parliament in Edinburgh and the National Assembly for Wales in Cardiff opened in 1999, and the possibility of devolution for the English regions has also been discussed.
Palace of Westminster, home of the world's oldest parliamentary democracy
In Northern Ireland, after decades of violent conflict, the Good Friday agreement of 1998 led to a new assembly with devolved powers, bringing hopes of lasting peace. The assembly was suspended in 2002 amid a row over alleged IRA activities. Its suspension was to last for three and a half years.
In a bid to restart the political process and after consultations with Dublin, the UK passed legislation paving the way for the recall of the Northern Ireland Assembly in May 2006.
But assembly leaders missed a November deadline to form a power-sharing executive. Assembly elections in the following March led to the eventual swearing-in of the leaders of the power-sharing government on 8 May 2007, ending five years of direct rule from London.
The UK is ethnically diverse, partly as a legacy of empire. Lately, the country has been struggling with issues revolving around multiculturalism, immigration and national identity.
This is against a background of concerns about terrorism and Islamist radicalism, heightened after the suicide bomb attacks on London's transport network in 2005.
Some politicians and commentators say a stronger sense of shared British values is needed to foster integration within a mixed society. And while some advocate tough policies on limiting immigration, others attempt to put the case for it as a positive force.
One of the more recent trends in migration has been the arrival of workers from the new EU member states in Eastern Europe.
The UK has been at the forefront of youth culture since the heyday of the Beatles and Rolling Stones in the 1960s.
It has a rich literary heritage encompassing the works of English writers such as William Shakespeare and Charles Dickens, Scot Robert Burns, Welshman Dylan Thomas and Northern Irishman Seamus Heaney.
Traditional music has deep roots across the UK, which has also produced classical composers from Henry Purcell in the Baroque period to Benjamin Britten in the 20th century.
Elizabeth II became queen of the United Kingdom of Great Britain and Northern Ireland in 1952 upon the death of her father, George VI.
Queen Elizabeth II
She is the second longest serving head of state, after the Thai King Bhumibol Adulyadej, who was crowned in 1946.
She is also head of state of 16 independent countries including Canada and Australia.
As a constitutional monarch, her role in the legislative process is largely ceremonial.
Prime minister: David Cameron
David Cameron became prime minister at the head of a coalition government on 11 May 2010, returning his centre-right Conservative Party to power after 13 years of rule by the centre-left Labour Party.
David Cameron: First Conservative prime minister in 13 years
Mr Cameron formed a partnership with the third party, the Liberal Democrats, after an inconclusive parliamentary election from which the Conservatives emerged with the largest number of seats, but without an absolute majority.
It is the first formal coalition government in 70 years to govern the UK, where the electoral system usually guarantees a majority for the largest party.
The new PM was confronted by a daunting economic situation, with the UK only slowly emerging from a deep recession caused by the 2008 global financial collapse, and facing a rapidly mounting budget deficit.
Assuming office, Mr Cameron promised that cutting the deficit would be his top priority. In October 2010, Mr Cameron's government announced a programme of deep cuts in government spending - the UK's largest in generations.
In 2011, the prime minister was criticised for hiring a journalist implicated in the scandal surrounding the hacking of phones by the now defunct News of the World newspaper as his communications director. The journalist, Andy Coulson, a former News of the World editor, resigned and was later arrested in connection with the allegations.
Born the son of a wealthy stockbroker in 1966 in London, Mr Cameron was educated at Eton College - Britain's top private school - and Oxford University. Aged 43 on coming to power, he was the youngest prime minister since 1812.
The UK has a strong tradition of public-service broadcasting and an international reputation for creative programme-making.
The fledgling BBC began daily radio broadcasts in 1922 and quickly came to play a pivotal role in national life. The Empire Service - the forerunner of the BBC World Service - established a reputation worldwide. The BBC is funded by a licence fee, which all households with a TV set must pay.
Commercial TV began in 1955 with the launch of ITV. Commercial radio was introduced in the 1970s, although ship-based pirate radio stations flourished in the 1960s before being outlawed. Hundreds of privately-owned radio and TV stations now compete with the BBC for listeners and viewers.
Home-grown soap operas have long topped the TV ratings, and British viewers keenly follow the ups and downs of life in east London's Albert Square, the setting for the BBC's EastEnders, and Coronation Street - ITV's soap about northern-English working-class life. Programmes which catapult ordinary people into the public eye - known as reality TV - are enjoying a wave of popularity.
In a rapidly-changing digital world, British media providers are looking at new ways of reaching audiences via computers and personal multimedia devices.
Once-dominant terrestrial TV networks face strong competition from digital satellite and cable, which offer hundreds of channels, and digital terrestrial TV (DTT), which carries a smaller number of mainly free-to-air channels. Britain's media regulator, Ofcom, hopes to turn off the analogue TV signal by 2012. Terrestrial digital radio (DAB) has had a slower start.
The media are free and able to report on all aspects of British life. The variety of publications reflects the full spectrum of political opinion. In recent years, newspaper circulations have been sliding while online readership has surged. In 2010, News Corporation, owner of The Times, began charging readers for access to the online content of some of its UK titles.
There were nearly 51.5 million internet users in the UK by June 2010 - more than 80% of the population (Internetworldstats). Research by Google in 2010 found that the internet accounts for 7.2% of the UK's gross domestic product (GDP). The study said Britain is the world's leading country for e-commerce.
By 2009, some 44% of UK internet users had a profile on at least one social network. The BBC is Britain's most popular online news destination.
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