The greatest military achievements of the Sung came right at the beginning of the period, when they established their dynasty and reunified the empire in a series of campaigns which knocked out their Chinese rivals one by one. In 960 Chao K'uang-yin, an officer of the palace guard in the relatively minor state of Chao, staged a coup and proclaimed his own regime - the Sung. He then embarked on an extraordinary series of conquests, with the aim of subduing the various kingdoms among whom China had been divided since the collapse of the T'ang in 907.
His strategy was to pick off the weakest of his opponents first, and in this he was helped by the chronic hostility which prevented them from forming an alliance against him, or even coming to each other's aid when the real threat from the Sung was finally understood. Ching-nan and Ch'u, on the middle Yangtze, fell first, followed by Shu in the western region of Szechwan. Shu was initially overrun in only 44 days, though a subsequent popular uprising took five years to suppress, with a series of major battles being fought between the Sung army and the rebels on the plain around Chengtu.