The Goryeo dynasty survived under the Yuan until King Gongmin began to push the Mongolian garrisons of the Yuan back in the 1350s. By 1356 Goryeo regained its lost northern territories. When King Gongmin ascended to the throne, Goryeo was under the influence of the Mongol Yuan China. When King Gongmin ascended to the throne, Goryeo was under the influence of the Mongol Yuan China. His first act was to remove all pro-Mongol aristocrats and military officers from their positions. Mongols had annexed the northern provinces of Goryeo after the invasions and incorporated them into their empire as the Ssangseong and Dongnyeong Prefectures. The Goryeo army retook these provinces partly thanks to defection from Yi Jachun, a minor Korean official in service of Mongols in Ssangseong, and his son Yi Seonggye. During this tumultuous period, Goryeo momentarily conquered Liaoyang in 1356, repulsed two large invasions by the Red Turbans in 1359 and 1360, and defeated the final attempt by the Yuan to dominate Goryeo when General Choe Yeong defeated an invading Mongol tumen in 1364.