The Battle of Changping (長平之戰) was a military campaign during the Warring States period of China that was fought between the two strongest military powers of the central plains, the State of Qin, State of Zhao northwest of present-day Gaoping). After a bitter two-year stalemate stretching 262 to 260 BC, the battle ended in a decisive victory for Qin forces. A vast majority of Zhao captives were ruthlessly executed, an unrecoverable loss of manpower and strategic reserve that permanently crippled the State of Zhao.