A split erupted between the Chinese Communist Party and the KMT, which threatened the Northern Expedition. Wang Jing Wei, who led the KMT leftist allies, took the city of Wuhan in January 1927. With the support of the Soviet agent Mikhail Borodin, Wang declared the National Government as having moved to Wuhan. Having taken Nanking in March, Chiang halted his campaign and prepared a violent break with Wang and his communist allies. Chiang's expulsion of the CPC and their Soviet advisers, marked by the Shanghai massacre on 12 April, led to the beginning of the Chinese Civil War. Wang finally surrendered his power to Chiang. Joseph Stalin ordered the Chinese Communist Party to obey the KMT leadership. Once this split had been healed, Chiang resumed his Northern Expedition and managed to take Shanghai.