As part of the Mongol conquest of the Jurchen Jin dynasty and Eastern Xia, the Mongols took political control of Manchuria in 1233. In response to raids by the Nivkh and the Udege peoples, the Mongols established an administration post at Nurgan (present-day Tyr, Russia) at the junction of the Amur and Amgun rivers in 1263, and forced the submission of the two peoples. The Mongols were motivated by their worldview that heaven had bestowed them the right to rule the whole world, thus unconquered people were naturally rebels upon whom military conquest was justified. The Mongols were also in the process of incorporating the Chinese tributary system for their own political and commercial purposes: the Mongols could manage relations with the peripheral peoples of Northeast Asia while making sure that goods from the region would be available as tribute or trade goods. Sable furs from lower Amur and Sakhalin, for instance, were especially favoured by the Mongol-Chinese upper class at the time. From the Nivkh perspective, their surrender to the Mongols essentially established a military alliance against the Ainu who had invaded their lands.