The Bašmyl, Chinese transcription Baximi 拔悉蜜, 拔悉密 or 拔悉彌, Bila 弊剌 or Abusi 阿布思, were one of the nine "outer tribes" (wai jiubu 外九部) of the Uyghur 回紇 federation. They lived as pastoral nomads in the region of Beiting 北庭 (modern Jimsar 吉木薩爾, Xinjiang) during the Tang period 唐 (618-907) and later moved to the region of River Orkhon in Mongolia. The families lived scattered in the hills and plains. The Bašmyls were famous for their bravery and their skills in riding and shooting with bow and arrow. In the winter they used to hunt with sledges and built huts of the bark of birch trees. The men used to cut their hair and to wear caps of bark. The designation of the chieftain was qushuai 渠帥.
In 649 they delivered tributes to the Tang court for the first time. In the 740s they united with other Uyghur leaders to destroy the Later Turkish Khanate. They killed Usumish Khan 烏蘇米施可汗 and made the tribesleader Ashina Shi 阿史那施 the new Turkish Khan, with the title of Helapijia Khan 賀臘毗伽可汗. Yet in 745 the Uyghurs joined with the Qarluqs 葛邏祿 and forced the Bašmyls into submission. They became part of the Uyghur khanate.