The Ming dynasty took control of Liaoning in 1371, just three years after the expulsion of the Mongols from Beijing. During the reign of the Yongle Emperor in the early 15th century, efforts were made to expand Chinese control throughout entire Manchuria by establishing the Nurgan Regional Military Commission. Mighty river fleets were built in Jilin City, and sailed several times between 1409 and ca. 1432, commanded by the eunuch Yishiha down the Songhua and the Amur all the way to the mouth of the Amur, getting the chieftains of the local tribes to swear allegiance to the Ming rulers.