 Kucha , a kingdom in the Tarim Basin , was a vassal of the Western Turkic Khaganate . Under the reign of Emperor Gaozu , the king <unk> ( Chinese : <unk> ) provided the Tang court with tribute in 618 . In 630 , <unk> 's successor Suvarnadeva ( Chinese : <unk> ) submitted to the Tang as a vassal . A Buddhist of the Hinayana sect , Suvarnadeva had hosted the Buddhist monk Xuanzang when he arrived in Kucha during the same year . 
