Dại Man

Đại Man belonged to the highland district later known as Chiêm Hóa, north of Tuyên Quang along the Gâm River. In the fourteenth century the area formed part of Vị Long, an upland châu whose chiefs governed mountain valleys between the Red River lowlands and the routes toward Hà Giang and Bắc Kạn. These highland and river-valley communities cultivated valley floors, gathered forest products and maintained local autonomy beneath distant Lê officials.

The Ming occupation renamed the châu Đại Man, a name retained during the Lê period within Yên Bình prefecture. It became one of five châu in Tuyên Quang and remained a loosely administered frontier district. Powerful Vũ lords dominated the wider region in the sixteenth and seventeenth centuries, while rivers and mountain paths linked scattered villages, markets and garrisons rather than a single dominant town. The Gâm carried upland goods south toward Tuyên Quang.

After Nông Văn Vân's rebellion, the Nguyễn court abolished the name in 1835 and established Chiêm Hóa châu. The transfer from frontier lordship to provincial administration did not erase older routes: the Gâm and its valleys remained the region's main north-south corridor. Đại Man therefore denotes a highland political landscape preserved in the later district, rather than a separately documented city.