 Zheng remained loyal to the throne and secretly met with Japanese officials and groups such as the Black Dragon Society to discuss a restoration of the Qing dynasty in Manchuria.Following the Mukden Incident and the invasion of Manchuria by the Imperial Japanese Army in 1931, Zheng played an important role in the establishment of Manchukuo, becoming its first prime minister the following year.Zheng also composed the lyrics of the National Anthem of Manchukuo.