Chì bì zhī zhàn
Battle of Redcliff of 208 at Chibi in Huangzhou district 黃州區|黄州区 of Huanggang city 黄冈, a decisive defeat of Cao Cao 曹操 at the hands of southern kingdom of Wu
famous episode in the Romance of the Three Kingdoms 三國演義|三国演义
Zhōu Yú dǎ Huáng Gài
fig. with the connivance of both sides
fig. by mutual consent
cf Wu patriot Huang Gai submits to mock beating at the hands of General Zhou Yu to deceive Cao Cao 曹操 before the 208 battle of Redcliff 赤壁之戰|赤壁之战[Chi4 bi4 zhi1 zhan4]