K'o-sa

{{Short description|Uyghur tribe}}

The K'o-sa ({{zh|c=可萨|p=Kěsà}}) is an ancient Uyghur tribe mentioned by ancient Chinese texts. D. M. Dunlop believed that they were connected with the Khazars, and thus postulated a Uyghur, rather than Hunnish origin for that people. The K'o-sa, who belonged to a Tujue tribe, were first mentioned under Du Huan's accounts on Tongdian as possessing the areas northwest to the Byzantine Empire.{{Cite book |last=Hirth |first=Friedrich |url=https://books.google.com/books?id=SRUwEAAAQBAJ&dq=%22K'o-sa%22&pg=PT55 |title=China and the Roman Orient: Researches into their Ancient and Medieval Relations as Represented in Early Chinese Records |date=2021-06-17 |publisher=Bloomsbury Publishing |isbn=978-0-7556-3939-7 |language=en}} They existed under a variant name in Suishu and formed part of the Tiele confederation whose presence was around or close to the Caspian Sea.