India is the world's largest democracy and, according to UN estimates, its population is expected to overtake China's in 2028 to become the world's most populous nation.
As a rising economic powerhouse and nuclear-armed state, India has emerged as an important regional power.
But it is also tackling huge, social, economic and environmental problems.
Home to some of the world's most ancient surviving civilisations, the Indian subcontinent - from the mountainous Afghan frontier to the jungles of Burma and the coral reefs of the Indian Ocean - is both vast and varied in terms of people, language and cultural traditions.
President: Ram Nath Kovind
Ram Nath Kovind, a Dalit - one of India's lowest castes - was picked by an electoral college to become president in July 2017.
He is a Supreme Court lawyer and has earned widespread respect as the governor of the northern state of Bihar.
India's presidency is largely ceremonial, but can play a significant role if, for example, no party wins an outright majority in national elections.
Prime Minister: Narendra Modi
Hindu nationalist Narendra Modi stormed to power on a surge of popular expectation and anger at corruption and weak growth.
Despite Mr Modi's polarising image, his Bharatiya Janata Party (BJP) scored an unprecedented landslide victory in the May 2014 parliamentary elections.
It was the first time in 30 years that a single party had won a clear parliamentary majority.
Mr Modi fought on his record as chief minister of the economically successful state of Gujarat, promising to revitalise India's flagging economy.
But his time in Gujarat was overshadowed by accusations that he did too little to stop the religious riots in 2001, which saw more than 1,000 people - mainly Muslims - killed.
India has a burgeoning media industry, with broadcast, print and digital media experiencing tremendous growth.
There are around 197 million TV households, many of them using satellite or cable. FM radio stations are plentiful but only public All India Radio can produce news.
The press scene is lively with thousands of titles. India has the second largest number of internet users in the world, after China.
Some key dates in India's history:
2500 BC - India is home to several ancient civilisations and empires.
1600s - The British arrive and establish trading posts under The British East India Company - by the 1850s they control most of the subcontinent.
1858 - India comes under direct British rule.
1920 - Nationalist leader Mahatma Gandhi heads a campaign of non-violent protest against British rule which eventually leads to independence.
1947 - India is split into two nations at independence - Hindu-majority India and Muslim-majority Pakistan.
1971 - India and Pakistan go to war over East Pakistan, leading to the creation of Bangladesh.
1974 - India conducts its first underground nuclear test.
1990s - Government initiates a programme of economic liberalisation and reform, opening up the economy to global trade and investment.
2000 - India's population tops one billion.
2014 - Hindu nationalist BJP party scores biggest election victory by any party in 30 years.