In 1368, soon after declaring the new Hongwu era of the Ming dynasty, the rebel leader Zhu Yuanzhang sent an army to Dadu/Khanbaliq and conquered it. Since the Yuan continued to occupy Shangdu and Mongolia, Dadu was used to supply the military garrisons in the area and was renamed Beiping (Wade–Giles: Peip'ing, "Northern Peace"). Under the Hongwu Emperor's feudal policies Beiping was given to Zhu Di, one of his sons, who was created "Prince of Yan".Overlapping layout of Beijing during the Liao, Jin, Yuan and Ming dynasties