The Basmyls (Basmyl; Basmals, Basmils, Basmïl, , Middle Chinese ZS: *bɣɛt̚-siɪt̚-miɪt̚/mɣiɪt̚/miᴇ; also 弊剌 Bìlà, MC *bjiejH-lat) were a 7th- to 8th-century Turkic nomadic tribe who mostly inhabited the Dzungaria region in the northwest of modern-day China.
Originally a forest people, Basmyls eventually grew in importance and played a prominent role in the Turkic politics from the 6th century. At one point Basmyls even overthrew the Second Turkic Khaganate's dynastic clan and briefly held the Khaganate with the help of Karluks and Uyghurs, who later turned against Basmyls. Basmyl supreme leaders were the first to use the term Ydyk-kut, which replaced khagan; Qocho Uyghur rulers of Turpan likewise titled themselves Ydyk-kuts. The title contains two components: the first component Ïdïq/Ydyk means "[heaven]-sent, sacred"; the second component kut/qut in the title is often found in Old Turkic onomastics and titulature and has the lexical meaning "grace" or "blessing";.
In the year 720 CE, the dynastic Basmyl clan were reported to be concentrated at Beiting Protectorate, near Gucheng (Qitai), in the Bogda Shan range, and to be Ashina Turks (Ch. 突厥 pinyin Tu-jue).
Mahmut Kashgari, an 11th-century historian, lists the Basmyls as one of ten prominent Turkic tribes and enumerates the locations of the Turkic polities from the borders of the Eastern Roman Empire to the borders of China in the following sequence:
Bäčänäk;
Qifčāk;
Oğuz;
Yemēk;
Bašğirt;
Basmyl;
Qāi;
Yabāqu;
Tatār;
Qirqiz.
Kashgari also noted that "Among the nomadic peoples are the Čömül - they have a gibberish (raṭāna [رَطَانَة]) of their own, but also know Turkic; also Qāy, Yabāqu, Tatār and Basmil - each of these groups has its own language, but they also know Turkic well"."
The Basmyls may be ancestral to the Argyn of the Middle Juz of modern Kazakhstan.Gumilyov, L. Searches for an Imaginary Kingdom: The trefoil of the Bird's Eye View' Ch. 5: The Shattered Silence (961-1100) Marco Polo apparently mentioned them as "Argons" in a country called "Tenduc" (around Kuku-Khotan, or modern-day Hohhot), during the 13th century.