The nation-state known in modern times as Indonesia encompasses an archipelago of 17,508 islands (6,000 inhabited) stretching along the Equator. The area is populated by peoples of various migrations, creating a diversity of cultures, ethnicities, and languages. These diverse peoples were influenced in varying degrees by trade and contact with the civilizations of the Middle East, South Asia, and East Asia, before the Portuguese initiated a direct relation between Indonesia and Europe, and colonists from the Netherlands finally consolidated most of the archipelago into a single administrative unit, under the Dutch East India Company.

The outbreak of World War II saw Indonesia put in the middle of warfare between the Dutch and Imperial Japan. The defeat of the Dutch saw them driven out and replaced with Japanese occupation forces, but the weakening of these two world powers provided an opening for Indonesian Nationalists, led by Sukarno, and other independence movements to launch an armed conflict. After a brief time, during which the Dutch sought to re-colonize the country, the Indonesian Nationalists won recognition for the newly formed Republic of Indonesia. In doing so, it was among the first Third World nations to gain its independence after World War II.

After gaining independence, the Republic of Indonesia has largely been ruled by a strong central government in Jakarta. After Indonesia's founding President Sukarno was weakened by prolonged warfare against Malaysia and its Commonwealth allies in the Konfrontasi, and by internal conflict between the Indonesian Army and the Communist Party of Indonesia, General Suharto took power in 1966. The period of his rule, known as the era of the New Order, would last 32 years and would make Indonesia a rapidly industrializing nation, though not without the problems of extensive corruption and popular discontent. After a wave of protests demanding democracy, Suharto stepped down, beginning the present period of Indonesian history, known as the Reformation era.