There are few written documents with which to trace Bunun history. Oral history indicates, however, that the Bunun lived in the Puli plain in the eighteenth century, and thereafter were forced by Han Chinese immigrants and Plains Aborigines to move to their current location. Most Bunun now regard Yu-shan as their ancestral homeland. Before 1895, the Bunun territory in central Taiwan had expanded east and south from the Yu-shan area as a result of population growth, in the process coming into contact with other aboriginal peoples such as Atayal, Tsou, Ami, Puyuma, Paiwan, and Han Chinese. The Japanese colonial government also had some impact on the Bunun during its occupation (1895-1945). After World War II, the Republic of China (R.O.C.) government and Christianity have been influential. The extent of the impact of neighboring ethnic groups, the Japanese government, the current Han Chinese-dominated government, and Christianity is difficult to establish, but it is clear that the Bunun have been reinventing their culture and society in response to these external contacts.