Bai Qi
The importance of Shu in the Sichuan Basin was its great agricultural output and its control over the upper reaches of the Yangtze River, leading directly into the Chu heartland. King Huiwen of Qin opted to support Sima Cuo. In 316 BCE, Qin invaded and conquered Shu and nearby Ba, expanding downriver in the following decades. In 278 BCE, the Qin general Bai Qi finally conquered Chu's capital at Ying. Following the fall of Ying, the Chu government moved to various locations in the east until settling in Shouchun in 241 BCE. After a massive two-year struggle, Bai Qi lured the main Zhao force of 400,000 men onto the field, surrounding them and forcing their surrender at Changping in 260 BCE. The Qin army massacred their prisoners, removing the last major obstacle to Qin dominance over the Chinese states.