Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian and Pacific oceans. Comprising between 13,000 and 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guinea, it is the world's largest archipelagic state and the 14th-largest country by area. Indonesia has extensive tropical forests and marine ecosystems that support one of the world's highest levels of biodiversity.
The Indonesian archipelago has been inhabited since prehistoric times, with early human presence evidenced by fossils of Homo erectus and Homo sapiens, and megalithic sites. It became connected to regional and international maritime trade networks by the first millennium BCE. Hindu and Buddhist kingdoms developed by early centuries CE, followed by the spread of Islam and the growth of Islamic states from the late medieval period. European powers later competed to monopolise trade in the Spice Islands of Maluku during the Age of Discovery. Dutch commercial and colonial control expanded from the 17th century and was consolidated over most of the archipelago during the 19th and early 20th centuries, before Indonesia proclaimed its independence in the aftermath of World War II.
Since independence, Indonesia has experienced separatist conflicts, corruption, political upheaval and natural disasters, alongside democratisation and rapid economic growth. The country today is a presidential republic with an elected legislature and consists of 38 provinces, some of which enjoy greater autonomy than others. Home to over 280 million people, Indonesia ranks fourth in the world by population and has the largest Muslim population of any country. More than half of Indonesians live on Java, the most heavily populated island in the world, while the capital Jakarta is the world's most populous city.
Indonesia has hundreds of ethnic groups and more than 700 languages, alongside diverse regional cultures. This diversity is reflected in the national motto, Bhinneka Tunggal Ika, meaning "unity in diversity". Indonesian, a standardised variety of Malay, is the official and national language and its lingua franca. Indonesia has the largest economy in Southeast Asia, with services and industry accounting for most output and economic activity concentrated on Java. Sea and air transport are the primary means of connecting the country's many islands. Indonesia is a middle power active in regional and global affairs and is a member of the United Nations, G20, the Non-Aligned Movement, ASEAN, and the Organisation of Islamic Cooperation.
The name Indonesia is usually explained as a combination of India and the Greek word nesos, together meaning 'Indian islands'. In 1850, George Windsor Earl, an English ethnologist, proposed the terms Indunesians and Malayunesians for the inhabitants of the "Indian Archipelago or Malay Archipelago", preferring the latter because he considered Indunesians too general. In the same journal, James Richardson Logan adopted Indonesia as a geographical term for the Indian Archipelago.
Usage remained limited for several decades. German ethnographer Adolf Bastian from the University of Berlin gave the term greater scholarly currency by using it in the title of his five-volume work Indonesien oder die Inseln des Malayischen Archipel, published from 1884 to 1894. Dutch scholars nevertheless tended to use Malay Archipelago (Dutch: Maleische Archipel) or the Netherlands East Indies (Nederlandsch Oost Indië). Popular alternatives included Indië, de Oost ("the East"), and, less often, Insulinde.
After 1900, Indonesia became increasingly common in academic and public usage, and Indonesian nationalist organisations adopted it as an expression of national unity and freedom from colonial rule. Among its early Indonesian promoters was Soewardi Soerjaningrat (Ki Hajar Dewantara), who established the Indonesisch Persbureau in The Hague in November 1918, a press bureau that used Indonesia in its name.
Prehistory, early states, and Islamisation
The island of Java has yielded numerous hominin fossils generally attributed to Homo erectus, including the type specimen discovered by Eugene Dubois at Trinil. Stone artefacts on Flores show that hominins had reached the island by at least 1.02 million years ago. Homo sapiens had dispersed into Southeast Asia by at least 50,000 years ago. In Sulawesi, narrative cave art has been dated to a minimum age of 51,200 years. Flores also yielded remains of the small-bodied hominin Homo floresiensis. Megalithic traditions later developed at different times across the archipelago, and stone monuments were used for burial and to honour or commemorate ancestors.
Beginning in the third millennium BCE, Austronesian-speaking communities moved south from Taiwan through the Philippines and into the Indonesian archipelago, where related languages eventually spread across most of the islands. Settlement and subsistence patterns varied across the islands, with communities combining fishing, hunting, gathering, and cultivation. From around 500 BCE, regional trading networks increasingly connected the archipelago with South and East Asia. Imported goods, knowledge, and technologies circulated through these networks, and during the early centuries CE some coastal communities in Borneo, Sumatra, and Java developed into trading ports. Indian merchants and religious specialists brought Sanskrit literacy, Hindu and Buddhist practices, and models of kingship that local rulers adopted.
Srivijaya, founded in southeastern Sumatra in the late 7th century CE, grew as a maritime trading polity and a centre of Buddhist learning and religious networks. In central Java, rulers supported the construction of major Hindu and Buddhist monuments between the 8th and 10th centuries, including Borobudur and Prambanan. Majapahit emerged in eastern Java in the late 13th century after Raden Wijaya used a Mongol expedition to defeat his rivals and then forced the Mongols to withdraw. Its rulers claimed suzerainty over a wide network of ports across the archipelago, although beyond Java this authority was often exercised indirectly through tributary, ritual, and commercial relationships rather than continuous territorial control.
By the late 13th century, Muslim rulers were established in parts of northern Sumatra. Perlak was described by Marco Polo as Muslim in 1292, and a royal tomb at Pasai dated 1297 records a Muslim ruler there. Samudra-Pasai became an important pepper port and a major centre for Islamic learning. Islam spread further through maritime trading networks, with Muslim communities becoming established at ports along Java's north coast and elsewhere in the archipelago. Majapahit declined during the 15th century, and Demak emerged as an independent north-coast sultanate and an important centre of Javanese Islam. Early conversions were associated with the Wali Sanga, the nine saints traditionally credited with the spread of Islam in Java. Islamic practice there also incorporated elements of older Javanese culture.
European contact and colonial rule
Before European arrival, spices from Maluku were already traded through Asian maritime networks in which Javanese and other regional merchants participated. The Portuguese captured Malacca in 1511 and reached Maluku the following year, where they sought control of the spice trade. Dutch expeditions followed in the 1590s, and in 1602 competing Dutch companies were merged into the Dutch East India Company (Vereenigde Oost-Indische Compagnie, VOC). Its charter authorised it to wage war, build fortresses, and conclude treaties in Asia. In 1619, the VOC captured Jayakarta (present-day Jakarta), renamed it Batavia, and turned it into its headquarters. It developed as an administrative and commercial centre and attracted Chinese migrants and others from the archipelago. The VOC was dissolved in 1800, and its possessions were passed to the Dutch state.
During the 19th century, Dutch power expanded across the archipelago and met sustained resistance in Java, Sumatra, Bali, and Aceh. In western New Guinea, the Dutch established an outpost in 1828, but abandoned it in 1836 and began permanent occupation only after 1898. By the early 20th century, military campaigns and boundary agreements had established Dutch control over a territory that largely corresponded to present-day Indonesia, known then as the Netherlands Indies. The colonial administration ruled several territories directly and governed others through local states whose rulers retained limited authority under Dutch supremacy.