朝秦暮楚 reflects the political reality of the Warring States period (
战国, 475-221 BC), when Qin (
秦) in the west and Chu (
楚) in the south were the two superpowers, and the small states between them constantly hedged their alliances. The phrase appears in Song-dynasty Chao Buzhi's (
晁补之)
《北渚亭赋》:
托生理于四方，固朝秦而暮楚 - 'committing one's livelihood to the four directions, surely serving Qin in the morning and Chu in the evening'.
