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 consolidated their hold over two centuries, eventually uniting the archipelago in around 1900.
After Japan's wartime occupation ended, independence was proclaimed in 1945 by Sukarno, the independence movement's leader.
Muslim celebration in Solo City
Indonesia has the world's largest Muslim population
The Dutch transferred sovereignty in 1949 after an armed struggle.