Java (Indonesian, Javanese, and Sundanese: Jawa) is an island of Indonesia and the site of its capital city, Jakarta. Once the centre of powerful Hindu kingdoms and the core of the colonial Dutch East Indies, Java now plays a dominant role in the economic and political life of Indonesia. With a population of 124 million, it is the most populous island in the world; it is also one of the most densely populated regions on Earth.

Formed mostly as the result of volcanic events Java is the 13th largest island in the world and the fifth largest island of Indonesia. A chain of volcanic mountains form an east-west spine along the island. It has three main languages, and most residents are bilingual, with Indonesian as their second language. While the majority of Javanese are Muslim, Java has a diverse mixture of religious beliefs and cultures.

The origins of the name 'Java' is not clear. One possibility is early colonists from India named the island after the jáwa-wut plant, which was said to be common in the island during the time, and that prior to colonization the island had different names. There are other possible sources: the word jaú and its variations mean "beyond" or "distant" and in Sanskrit yava means barley, a plant for which the island was famous.

Outsiders often refer to Java and the neighboring islands by the same name, or use names inconsistently for different islands. For example, Marco Polo refers Sumatra as "little Java" and Ptolemy refers to Sumatra as Jaba-diu

The island of Java is known for several important finds of early hominid specimens. In particular, the 1891 discovery of cranial fossil remains commonly known as "Java man" (now designated as Trinil 2, after the Trinil site on the Bengawan Solo River) is notable as the first early hominid specimen found outside Europe. This find, and several subsequent ones at various locations along the river's valleys, are now generally classified in the species Homo erectus.

Scientists speculate that, two million years ago, heavy rainfall in the Sunda and Digul plateaus produced dense tropical vegetation, which supported the prehistoric hominids evidenced in many fossil finds.

Hindu and Buddhist Kingdoms
Much evidence of Java's past kingdoms remains; such as the famous Buddhist Borobudur and Hindu Prambanan temples. Indeed, the Javanese culture, and language itself, was heavily influenced by the cultures and languages of the Indian subcontinent. In the sixth and seventh centuries, many maritime kingdoms arose in Sumatra and Java, which controlled the waters in the Straits of Malacca, and flourished with the increasing sea-trade between China and India and beyond. During this time, scholars from India and China visited these kingdoms to translate literary and religious texts.

The most prominent of the Hindu kingdoms was the Majapahit empire based in East Java, from where it held sway over a large part of what is now Indonesia plus Malaysia and some said even to Madagascar. The name of the Majapahit empire is still invoked by contemporary Indonesian leaders to promote "unity", and the legitimacy of the state. The remnants of the Majapahit's priests, royalties, and artisans, fled to Bali during the sixteenth century, as Muslim kingdoms in the coastal part of the island gained influence.

Muslim kingdoms and the Dutch colonization
The earliest Muslim "evangelists" were called the Wali Songo, the "nine ambassadors". Several of them were of Chinese origin, leading to speculation about Zheng He's influence on the trade in the Straits of Malacca. Many of their tombs are still well-preserved, and often visited "Ziarah" for superstitious and religious reasons. Most of the brand of Islam that is adopted in Java is mixed with long-standing indigenous beliefs, and has a decidedly "local flavor". For example, the legend of Nyi Roro Kidul was invented as a mix of the beliefs common on the southern coast of Java, and Islamic influences.

The Dutch East India Company (VOC) established its trading and administrative headquarters in Batavia (now the capital city of Jakarta). This capital, along with other coastal cities such as Semarang and Surabaya, was the focus of Dutch attention during most of the colonial period. The VOC maintained control over the mountainous interior of the island through indigenous client states, such as Mataram in central Java.

The nineteenth century saw the Dutch government take over administration of Indonesia from the VOC, and in the mid-nineteenth century, they implemented new policies, usually called the Culture System (Dutch: cultuurstelsel). These policies, intended to increase the profitability of the colony by requiring increased production of cash crops, led to famine and widespread poverty on Java. By the beginning of the twentieth century, protest over the policy's effects, and political changes in the Netherlands and in the Indies led to the Ethical Policy. This policy of increased investment in the colony gave many more Javanese elites access to a Dutch education, both in Java and in the Netherlands itself. It was from this elite that the most prominent nationalist leaders came. They formed the core of the new government, when Indonesia became a Republic after World War II.

Republican era
With the establishment of Jakarta as the capital and the Javanese roots of the majority of Indonesian political figures, the island has a dominant role in the political and economic life of the nation. While parts of rural Java are among the poorest in the nation, the urban areas of the island are Indonesia's wealthiest and most urbanized areas. Presidents Sukarno (1945-1965), Suharto (1965-1998), Abdurrahman Wahid a.k.a GusDur (1999-2001), Megawati Sukarnoputri (2001-2004), and Susilo Bambang Yudhoyono (2004-now) were all from Java. The only president who was not from Java was Baharuddin Jusuf Habibie (1998-1999).