China is the world's most populous country, with a continuous culture stretching back nearly 4,000 years.
Many of the elements that make up the foundation of the modern world originated in China, including paper, gunpowder, credit banking, the compass and paper money.
After stagnating for more decades under the rigid rule of Communist leader Mao Tse-Tung, China now has the world's fastest-growing economy and is undergoing what has been described as a second industrial revolution.
The People's Republic of China (PRC) was founded in 1949 after the Communist Party defeated the previously dominant nationalist Kuomintang in a civil war. The Kuomintang retreated to Taiwan, creating two rival Chinese states - the PRC on the mainland and the Republic of China based on Taiwan.
Beijing says the island of Taiwan is a part of Chinese territory that must be reunited with the mainland. The claim has in the past led to tension and threats of invasion, but since 2008 the two governments have moved towards a more cooperative atmosphere.
The leadership of Mao Tse-Tung oversaw the often brutal implementation of a Communist vision of society. Millions died in the Great Leap Forward - a programme of state control over agriculture and rapid industrialisation - and the Cultural Revolution, a chaotic attempt to root out elements seen as hostile to Communist rule.
However, Mao's death in 1976 ushered in a new leadership and economic reform. In the early 1980s the government dismantled collective farming and again allowed private enterprise.
The rate of economic change hasn't been matched by political reform, with the Communist Party - the world's biggest political party - retaining its monopoly on power and maintaining strict control over the people. The authorities still crack down on any signs of opposition and send outspoken dissidents to labour camps.
Nowadays China is one of the world's top exporters and is attracting record amounts of foreign investment. In turn, it is investing billions of dollars abroad.
The collapse in international export markets that accompanied the global financial crisis of 2009 initially hit China hard, but its economy was among the first in the world to rebound, quickly returning to growth. In February 2011 it formally overtook Japan to become the world's second-largest economy.
As a member of the World Trade Organization, China benefits from access to foreign markets. But relations with trading partners have been strained over China's huge trade surplus and the piracy of goods. The former has led to demands for Beijing to raise the value of its currency, which would make Chinese goods more expensive for foreign buyers and possibly hold back exports.
Some Chinese fear that the rise of private enterprise and the demise of state-run industries carries heavy social costs such as unemployment and instability.
Moreover, the fast-growing economy has fuelled the demand for energy. China is the largest oil consumer after the US, and the world's biggest producer and consumer of coal. It spends billions of dollars in pursuit of foreign energy supplies. There has been a massive investment in hydro-power, including the $25bn Three Gorges Dam project.
The economic disparity between urban China and the rural hinterlands is among the largest in the world. In recent decades many impoverished rural dwellers have flocked to the country's eastern cities, which have enjoyed a construction boom.
Social discontent manifests itself in protests by farmers and workers. Tens of thousands of people travel to Beijing each year to lodge petitions with the authorities in the hope of finding redress for alleged corruption, land seizures and evictions.
Other pressing problems include corruption, which affects every level of society, and the growing rate of HIV infection. A downside of the economic boom has been environmental degradation; China is home to many of the world's most-polluted cities.
Human rights campaigners continue to criticise China for executing hundreds of people every year and for failing to stop torture. The country is keen to stamp down on what it sees as dissent among its ethnic minorities, including Muslim Uighurs in the north-west. The authorities have targeted the Falun Gong spiritual movement, which they designate an "evil cult".
Chinese rule over Tibet is controversial. Human rights groups accuse the authorities of the systematic destruction of Tibetan Buddhist culture and the persecution of monks loyal to the Dalai Lama, the exiled spiritual leader who is campaigning for autonomy within China.
* Full name: People's Republic of China
* Population: 1.35 billion (UN, 2010)
* Capital: Beijing
* Largest city: Shanghai
* Area: 9.6 million sq km (3.7 million sq miles)
* Major language: Mandarin Chinese
* Major religions: Buddhism, Christianity, Islam, Taoism
* Life expectancy: 72 years (men), 76 years (women) (UN)
* Monetary unit: 1 Renminbi (yuan) (Y) = 10 jiao = 100 fen;
* Main exports: Manufactured goods, including textiles, garments, electronics, arms
* GNI per capita: US $3,590 (World Bank, 2009)
* Internet domain: .cn
* International dialling code: +86
Head of state: President Hu Jintao
Little was known about the low-profile Mr Hu when he was elected by the National People's Congress in March 2003.
His position as the presidential heir-apparent had been cemented at the 16th Communist Party Congress in 2002, when he succeeded Jiang Zemin as head of the party. He was re-elected as president in March 2008.
Mr Jiang's decision to stand down as head of the powerful Central Military Commission in 2004, three years earlier than planned, was said to have completed the first orderly transition of power since the communist revolution in 1949.
Mr Hu has made the fight against corruption a priority; he has promised to promote good governance, saying the fate of socialism is at stake. But he has rejected Western-style political reforms, warning that they would lead China down a "blind alley".
Responding to rising social tensions and China's wealth gap, he advocates a drive to build a "harmonious society" and has promised greater spending on health and education in rural areas.
Mr Hu is scheduled to retire as head of the Communist Party in 2012 and as president in 2013. Vice-President Xi Jinping is seen as a likely candidate for the succession, especially after being appointed vice-chairman of the Central Military Commission, which is regarded as a key stepping stone to the top job.
Hu Jintao was born in Anhui province in 1942, according to his official biography.
A committed Communist Party member since 1964, his party career took off in the late 1970s. In the 1980s he served as party chief in Guizhou and Tibet, where he oversaw crackdowns on pro-independence protests. In 1992 Mr Hu became the youngest member of the Politburo Standing Committee, the party's main decision-making body.
He is said to enjoy dancing and table tennis and has been described as a cautious, intelligent man. Party loyalty and obedience are believed to have contributed to his political rise.
Prime Minister: Wen Jiabao
As vice-premier, prime minister and a leading figure in the Communist Party politburo, Wen has shaped China's economic policy since the late 1990s. A geological engineer by training, he worked in the provinces before rising through the party bureaucracy in the 1980s.
He become right-hand man to Zhu Rongji, the architect of China's economic growth in the late 1990s and a stern opponent of corruption, and succeeded him as prime minister in 2003.
Like President Hu Jintao, Wen tries to be more approachable than his predecessors and to reach out to the hinterland that often feels left out of China's economic boom.
He has pioneered greater openness over health and environmental problems, such as the SARS outbreak in 2004, and acknowledged the impact of HIV and the damage caused by the Three Gorges Dam.
Wen has a high international profile, and undertook tours of the United States and Japan to improve relations. He has nonetheless maintained China's traditional tough stances in Taiwan, Tibet, the South China Sea and currency devaluation, and presided over a significant increase in the military budget.
From : BBC News