The origin of the Dusun population is uncertain at present. Existing archaeological and physical anthropological evidence, considered with the results of historical and comparative studies, suggests that the Dusun are descendants of populations migrating into northern Borneo in successive waves some time about 4,000 to 5,000 years ago (and possibly earlier). They brought with them a Neolithic, or food-producing, way of life, based on swidden cultivation supplemented by hunting and foraging. Change in Dusun life, derived from contacts with other cultures, has been taking place for a long period. The historical record indicates contact, particularly in coastal communities in western and northern Sabah, between Dusun and Indians, Chinese, Malays, and Europeans. Thus, beginning after the seventh century B.C. , Indian traders and travelers en route by boat to and from south China stopped briefly along the western and northern Borneo coasts to replenish supplies or seek shelter from severe South China Sea weather. These Indian travelers included various types of craftsmen and Brahman and Buddhist teachers and priests. During the time of the Western Han Empire (202 B.C. to A.D. 9), Chinese traders and religious pilgrims traveling to and from India also were in contact with the coastal peoples of western and northern Borneo, seeking local products. Chinese trade with India, with stops by ships along the coasts of Borneo, expanded several times until A.D. 1430, and included the establishment of some trading settlements, such as the one founded in A.D. 1375 at the mouth of the Kinabatangan river in the eastern part of north Borneo by a Chinese trader (Wang Sen-ping). These contacts between northern Borneo native peoples and Chinese traders and travelers over many centuries introduced a wide range of Chinese cultural forms to Bornean populations, and brought them the techniques and tools of irrigated rice agriculture using the water buffalo as a principal source of power in field preparation. Between the ninth and thirteenth centuries A.D. the early Malay Buddhist kingdom of Srivijaya, centered in the area of the present-day city of Palembang, Sumatra, dominated the southern and southwestern coasts of Borneo. Representatives of this kingdom made contact with people along the coasts of western and northern Borneo. Then the powerful Hindu kingdom of Majapahit, located in Java, exercised state power in the same coastal areas of Borneo beginning in the early fourteenth century A.D. Islamic influences and cultural forms spread to the area as the state of Malacca, ruled by a Muslim prince, exerted its domination in the fifteenth century A.D. Some European cultural influences reached the western and northern Borneo coasts as traders sought local products, particularly spices, following the conquest of Malacca by a Portuguese fleet in A.D. 1511. Regular and intensive contacts between Europeans and the coastal peoples of Borneo did not begin until after the mid-nineteenth century A.D. , as the British sought to establish protectorates to maintain the safety of trade routes through the South China Sea. In northern Borneo, a private chartered company was established by British investors in 1881, which ruled the area as a sovereign entity until 15 July 1946, when British North Borneo became a British colony. British colonial rule continued for seventeen more years, until North Borneo became the state of Sabah in Malaysia in September 1963. Thus the Dusun were in regular contact with British cultural and social forms for eighty-two years, during which power, authority, and law were usually imposed unilaterally and with little regard for Dusun tradition. These contacts brought Dusun to realize they were citizens of a Malaysian state, and also brought them into regular contact with a new national language (Bahasa Melayu) and an emphasis by the national government on Muslim religious traditions, values, and social practices.