until the late fourth century, a livestock-raising nomadic tribe ranging primarily over the territory of today’s Inner Mongolian Autonomous Region in China. The T’o-pa were part of the Hsien-pi tribal alliance until the mid-third century; thereafter they played an active political role as an independent tribe, and in the early fourth century they entered into a military alliance with China’s Western Chin empire.

Clan relations were still prevalent among the T’o-pa in the second and third centuries; the late third and early fourth centuries saw the beginnings of hereditary rule. By the end of the fourth century, the T’o-pa were a class feudal society and had founded their own state of T’o-pa (or Northern) Wei. By the year 439 the T’o-pa Wei, having wiped out a succession of non-Chinese peoples, were the sole rulers of northern China. In the late fourth century the T’o-pa—now leading a settled life—took up farming in addition to stock raising. They were later assimilated and were not mentioned in sources after the seventh century.