The Leco from North of La Paz were considered to have disappeared by the end of the 20th century; however in 1997, two groups of Leco re-emerged independently from each other, one in Larecaja and one in Apolo. In the former the claim was less violent than in the latter, where Quechua peasants share language, culture and kinship, and refuse to recognize the land rights and the identity of their “Indigenous Leco” neighbours. The thesis aims to understand ethnohistorically both resurgences, and tries to go beyond essentialism to understand the heterogeneous melting pot from where the Apoleños come. Apolobamba, because it connects highlands and lowlands, received Andean influences (puquina, aymara and quechua) early on. Its inhabitants, the Chuncho of the Incas then the Spaniards, show hybrid ethnolinguistic and socio-cultural features. The ethnic diversity was reduced in the 18th century Franciscan Missions, where the ethnolinguistic border between an Andean South and the “savages” of the North was drawn at the Tuichi river. The liberal Republican period, with the construction of a national identity, once again shrank regional diversity and increased “Andeanization”. Apolistas and then Apoleños emerged from these interethnic mixes defined more geographically than ethnically. The Leco revival happens in an auspicious national and international context, but the Leco language was still spoken two or three generations ago on the Mapiri's banks. It raises the question of social transformation and continuity: are we dealing with a case of acculturation, ethnogenesis, camouflage or resistance?