This study contributes to Naxi and Mosuo studies, Chinese, Yunnanese and Himalayan studies, and the fields of anthropology, history, ethnic studies and religion. It is a multidimensional anthropological study devoted to the history of Naxi social institutions and the political history of the southwestern Sino-Tibetan frontier. This study presents original data on both matrilineal and patrilineal Mosuo society, and original ethnographic information on patrilineal Mosuo families and marriage system. It also proposes a Mosuo matriarchal history, a significant claim for anthropological theory. It also contributes to the fields of Himalayan studies and pre-Buddhist religions and the relationship between religion and politics in tribal societies. It explains the origins of Naxi Dongba pictographic script in territorial cults and military expansion. On the basis of her own fieldwork, the author also describes the rapidly disappearing Mosuo Daba religion, of which little is known outside China. It presents an entirely original reading of primary and secondary Chinese sources.