This paper reviews what is known of Tibetan prehistory until the seventh century A.D., when the Tibetan empire was established. Topics covered in this paper include a consideration of the antiquity of a human presence upon the plateau, changing adaptive strategies following the end of the glacial epoch, the advent of the Neolithic, and the emergence of social and political complexity. Despite significant advances in our knowledge of the Tibetan past, much work remains to be done before models of process can be examined in any detail.