Spread across a chain of thousands of islands between Asia and Australia, Indonesia has the world's largest Muslim population and Southeast Asia's biggest economy.
Ethnically it is highly diverse, with more than 300 local languages. The people range from rural hunter-gatherers to a modern urban elite.
Sophisticated kingdoms existed before the arrival of the Dutch, who colonised the archipelago but gave in to an independence struggle in 1949.
Indonesia has become one of the world's major emerging economies, but faces demands for independence in several provinces and increasing attacks by Islamist armed groups.
President: Joko Widodo
Joko "Jokowi" Widodo won the elections of July 2014, one of a new breed of politician that has emerged in the fledgling democracy.
It was a close contest with the old guard who flourished under decades of autocratic rule.
He is seen by many as relatively untainted by the county's endemic corruption and in touch with ordinary Indonesians as a result of his humble background - he was a furniture maker and his father a wood seller.
Television is the main medium, but online media are catching up.
Facebook is hugely popular, and Indonesians are among the world's most active users of Twitter.
Reporters Without Borders says many journalists self censor because of legislation governing blasphemy and online content.
Some key dates in Indonesia's history:
1670-1900 - Dutch colonists bring the whole of Indonesia under one government as the Dutch East Indies.
1942 - Japan occupies Dutch East Indies.
1949 - The Dutch recognise Indonesian independence after four years of guerrilla warfare. Sukarno is president.
1966 - Sukarno hands power to General Suharto following an abortive coup.
1976 - Indonesia invades East Timor and incorporates it as a province.
1998 - Protests and rioting topple Suharto.
1999 - East Timor comes under UN administration.
2004 - First-ever direct presidential elections.