In contrast to the Eastern Turkic Khaganate, the Western Turkic Khaganate did not pose a major threat to the Tang dynasty in the early years of the dynasty's existence, as it was farther from Tang-held territory and had a general indifference towards Chinese ambitions. Moreover, the Western Turkic Khaganate constantly suffered from internal conflict and was unable to focus itself against external threats. Because of this pacifism, the Khaganate's tributaries in the Tarim basin remained unmolested by Tang forces. In turn, both the Western Turkic Khaganate itself and its vassal-allies in the region at times nominally submitted to Tang overlordship. For example, in 619, soon after Emperor Gaozu established the dynasty in 618 and was still battling for supremacy over China against a number of rival rulers, both the Western Turkic Khaganate's Tongyehu Khan Ashina Tong and Gaochang's king Qu Boya sent tributes to him. In 625, Ashina Tong sought marriage with a Tang princess, and Emperor Gaozu initially agreed, but the Eastern Turkic Khaganate's Illig Qaghan Ashina Duobi was displeased about the potential of a Tang-Western Turkic alliance and warned Ashina Tong against it, ensuring that the marriage never took place.