In 960, Zhao Kuangyin (known now as Emperor Taizu) helped reunite most of China after the fragmentation and rebellion between the fall of the Tang dynasty in 907 and the establishment of the Song dynasty. The plan set during Chai Rong's reign was to first conquer the north, then the south. During Emperor Taizu's reign, there was a change in strategy. He would conquer all the smaller states such as Later Shu, Southern Han and Southern Tang. The exception was the strong Northern Han in the north at Taiyuan supported by the Khitans of the Liao dynasty. Emperor Taizu's strategy was to first take the southern territories because the south was weaker than the north as the Liao dynasty supported Northern Han.