Tocharian, also spelled
Tokharian ( or ;Chinese: 吐火羅語), is an extinct branch of the
Indo-European language family, known from manuscripts dating from the 6th to the 8th century AD found in
oasis cities on the northern edge of the
Tarim Basin (now part of
Xinjiang in northwest China). The discovery of these languages in the early 20th century contradicted the formerly prevalent idea of an east–west division of Indo-European language family on the
centum–satem isogloss, and contributed to re-invigorated study of the family. The term "Tocharian", based on an identification with the
Bactrian Tokharoi of classical sources, is now generally considered a misnomer, but has become customary.