Indonesian is the official language of Indonesia and is referred in Indonesia to Bahasa Indonesia or simpy Bahasa. The roots and base is Malay or to be more precise classical malay spoken in sumatra. The oldest evidence of old malay existing in Indonesia is from the 7th century. Dutch colonization of Indonesia tried to spread dutch as the national languagebut japanese occupation stopped that development outlawing dutch. That was in 1942 and in 1945 Bahasa Indonesia was established as the national language.