Law of Indonesia is based on a civil law system, intermixed with local customary law and Dutch law. Before European presence and colonization began in the sixteenth century, indigenous kingdoms ruled the archipelago independently with their own custom laws, known as adat (unwritten, traditional rules still observed in the Indonesian society). Foreign influences from India, China and the Middle East have not only affected culture, but also the customary adat laws. The people of Aceh in Sumatra, for instance, observe their own sharia law, while ethnic groups like the Toraja in Sulawesi still follow their animistic customary law.
Dutch presence and subsequent colonization of Indonesia for over three centuries has left a legacy of Dutch colonial law, largely in the Indonesian civil code and criminal code. Following independence in 1945, Indonesia began to form its own modern Indonesian law, modifying existing precepts. Dutch legal decisions maintain some authority in Indonesia through application of the concordance principle. The three components of adat, or customary law; Dutch law; and modern Indonesian law co-exist in the current law of Indonesia.
