Tocharian B
Tocharian B, also known as Kuchean or West Tocharian, was a Western member of the Tocharian branch of Indo-European languages, extinct from the ninth century. Once spoken in the Tarim Basin in Central Asia, Tocharian B shows an internal chronological development; three linguistic stages have been detected. The oldest stage is attested only in Kucha. There is also the middle, and the late stage.Nomenclature
According to Peyrot, the self-designation for the language was kuśi 'Kuča'. In scholarly works, it is known as Tocharian B, sometimes referred to as West Tocharian or Kuchean.Overview
According to scholar Michael Peyrot, Tocharian B is dated between the 5th and 10th centuries AD, and was spread from Kuča to Yānqi and Turfan. Paul Widmer, following Tamai's and Adams's studies, situates Tocharian B roughly between 400 and 1200, its oldest layer dating from ca. 400 to 600, around "Kucha and environs".Documentation
According to J. H. W. Penney, Tocharian B is reported to be documented as Buddhist religious literature, and as secular material "pertaining to everyday life".