being the native language of only about 5% of the population. In contrast, Javanese and Sundanese were the mother tongues of 42–48% and 15% respectively. The combination of nationalistic, political, and practical concerns ultimately led to the successful adoption of Indonesian as a national language. In 1945, Javanese was easily the most prominent language in Indonesia. It was the native language of nearly half the population, the primary language of politics and economics, and the language of courtly, religious, and literary tradition. What it lacked, however, was the ability to unite the diverse Indonesian population as a whole. With thousands of islands and hundreds of different languages, the newly independent country of Indonesia had to find a national language that could realistically be spoken by the majority of the population and that would not divide the nation by favouring one ethnic group, namely the Javanese, over the others. In 1945, Indonesian was already in widespread use; in fact, it had been for roughly a thousand years. Over that long period, Malay, which would later become standardized as Indonesian, was the primary language of commerce and travel. It was also the language used for the propagation of Islam in the 13th to 17th centuries, as well as the language of instruction used by Portuguese and Dutch missionaries attempting to convert the indigenous people to Christianity. The combination of these factors meant that the language was already known to some degree by most of the population, and it could be more easily adopted as the national language than perhaps any other. Moreover, it was the language of the sultanate of Brunei and of future Malaysia, on which some Indonesian nationalists had claims. Over the first 53 years of Indonesian independence, the country's first two presidents, Sukarno and Suharto constantly nurtured the sense of national unity embodied by Indonesian, and the language remains an essential component of Indonesian identity. Through a language planning program that made Indonesian the language of politics, education, and nation-building in general, Indonesian became one of the few success stories of an indigenous language effectively overtaking that of a country's colonisers to become the de jure and de facto official language. Today, Indonesian continues to function as the language of national identity as the Congress of Indonesian Youth envisioned, and also serves as the language of education, literacy, modernization, and social mobility. Despite still being a second language to