Java ( Indonesian : Jawa ) is an island in Indonesia . With 135 million people, the most populous island of Java is the world, and is one of the areas with the highest population density in the world. Java is inhabited by 60 percent of the Indonesian population. The capital Jakarta is located in the west of Indonesia's Java suite. Most of Indonesia historic event took place in Java. The island was the center of an empire of Hinduism - Buddhism , Islam mighty kingdom, and the nucleus of the Dutch East Indies . Java is the heart of the War of Independence Indonesia | struggle for independence for Indonesia in the 1930s and 40s Java dominates politics, economics and culture in Indonesia. Java formed mainly as a result of the volcanic eruption service, with an area of the world's 13th largest and the 5th largest in Indonesia. A string of volcanic islands that form the backbone of an east-west direction. The island has three major languages, including Java language dominant, and the native language of about 60 million people in Indonesia, most of them living in Java. Most of the island's residents are bilingual, Indonesian as a first language or their second. Most residents Java is Muslim , but the island still has a diverse mix of religious beliefs, ethnicity, and culture.