I've recently gotten into linguistic history, and I learned about the Indo-European language family, even more interesting to me was that there are entire branches that have just vanished over time like the Anatolian branch, and Tocharian.
I'm curious what exactly happened to this far Eastern Indo-European group. There doesn't seem to be a major Tocharian ethnic group in today's world, how recently were Tocharians attested as being around still by other cultures in the region? Is there any record to indicate why they aren't around anymore? How did they even wind up so much further north and east relative to the other major Indo European groups to be in modern day China?
Although they're in modern day China, historically they were much west of China. They settled in the Tarim basin, in the dry, but fertile riverlands surrounding the Taklamakan desert. The reason they went extinct is because of migrations of old Uyghurs in the 9th century. The Uyghurs migrated to the Tarim basin after defeat by Khitas and created the kingdom of Qocho (because the Tocharians were mostly agrarian they didn't have any advanced kingdoms outside of silk road counties). Uyghurs settled the previously-Tocharian lands and they were presumed to have gone extinct in the 10th century. I personally think they were related to Indo-Iranians, similarly to the Scythian Saka people living in the west Tarim basin (who coincidentally went extinct around the same time due to Turkic settlers)