Indigenous people in the Central Mountain Range and the east enjoyed undisrupted traditional ways of life. The western region had been long been controlled by the Qing authorities, who considered the east as huawai (“beyond civilization”) or “the back of the mountains.” Even though people west of the boundary were forbidden to cross the boundary, interaction between the east and the west never ceased; some people frequently entered the mountains for various reasons. Both indigenous people and Han people from the west often traveled to the east to trade or develop land for cultivation. In the 19th century, Kavalan Subprefecture, Hengchun County, Beinan Subprefecture, Taitung Prefecture, and other government subdivisions were established. As more and more people from the west migrated to the east, indigenous people in the east felt their original way of life threatened.