With the disintegration of Yuan, which had influenced the Korean peninsula since the Mongol invasion of Korea of 1238, King Gongmin began efforts to reform Goryeo government. His first act was to remove all pro-Mongol aristocrats and military officers from their positions. These deposed people formed a dissident faction which plotted an unsuccessful coup against the king. High official Jo Il-shin even tried to take over the government, but this rebellion was put down by general Choi Young.