A branch of the Turkish Tölöš people, consisting of the two tribes of Syr and Tarduš. While the Tölöš had been an important vassal people of the Turks, the Syr-Tardush only came under the domination of the Western Turks at the begin of the 7th century. But the Syr-Tarduš were able to overcome the military power of the Tölöš and installed their ruler "Yijin Yishibo" 俟斤乙失鉢 as "Yedie" Qaγan 也咥可汗. Under Yinan 夷男 the Syr-Tarduš moved to the east and welcomed many Eastern Turks within their communities. Yinan was bestowed with the title of Zhenzhu Pijie Qaγan 真珠毗伽可汗 by the Tang Dynasty 唐. After the dissolving of the Eastern Turk federation the Syr-Tarduš controlled the northern grasslands in a second federation of the Tölöš people (the first being under Yedie Qaγan). Yinan's son Bazhuo 跋灼 - Duomi Qaγan 多彌可汗 - lost the grip on the different tribes and faced attacks by the Turks and the Uighurs. His nephew Duomozhi 咄摩支 was eventually defeated by the Tang troops under Li Ji 李勣, and the Syr-Tarduš federation dissolved in 646.