The Sino-Tibetan borderlands cover a vast mountainous expanse inhabited by agricultural and pastoral communities of various ethnicities, predominantly Tibetan-speaking groups. An area of mutual interest, rivalry and conflict, it has been the scene of lively religious and commercial exchanges, remarkable cultural flows and circulations that have involved many diverse peoples who were part of varying motley socio-political entities (kingdoms, estates, tribal federations, etc.) on various scales. Central Tibet, Mongolia and China have historically exerted a strong political influence that has greatly contributed to shaping local political formations, religious landscapes and cultural identities. For a proper understanding of this diversity, an anthropological history of this area cannot be limited to Sino- or Tibeto-centric narratives but needs to take into account multipolar perspectives and indigenous voices. However, very few sources provide a borderland-centred history and, where written sources do exist, they generally portray the view held by the centres of power. A more kaleidoscopic view of this mountainous area can complement a social history of Sino-Tibetan relations and of the associated processes that have contributed to shaping the region into a borderland by restoring the multiplicity of historical experiences and forms of agency of the communities in between.