After the death in 210 BC of the first Qin ( 秦 ) dynasty emperor Shihuangdi ( 始皇帝 ), Xiang Yu ( 項羽 ) and Liu Bang ( 劉邦 ) revolted and the two rivals raced to the capital to attempt to overthrow and seize the throne for themselves. Xiang Yu (232-202 BC) was from Chu ( 楚 ) and Liu Bang (256-195 BC) from Pei ( 沛 ). Liu Bang is sometimes also called Lord Pei. In Japanese, Xiang Yu is pronounced as Kouu ( こうう ), Liu Bang is pronounced as Ryuuhou ( りゅうほう ).
Liu Bang reached the Qin capital in 206 BC, only to have the stronger Xiang Yu come and drive him out. Xiang Yu gave Liu Bang the rule over Shu ( 蜀 ) but within four years Liu Bang overtook Xiang Yu in power and influence. The two clashed eventually and at the siege of Gaixia ( 垓下 ), Liu Bang ordered his men to sing songs from Xiang Yu's native Chu.
夜, 聞漢軍四面皆楚歌, 項王乃大驚曰, 漢皆已得楚乎.
夜, 漢軍の四面皆楚歌するを聞き, 項王乃ち大いに驚きて曰く, 漢 皆 已に楚を得たるか.
That night, Xiang Yu heard the army from Han ( 漢 ) singing songs from Chu and in surprise remarked, "Chu has already fallen to the Han?"
To this day, ( 四面楚歌 ) is a four kanji idiom in Japanese (shimen soka) and Chinese (Si Mian Chu Ge) that comes from this line in the story and means "surrounded by enemies" and "ostracize", but can be construed to have many other meanings in English.
Liu Bang went on to defeat Xiang Yu and founded the Han dynasty, becoming the first Chinese emperor from the peasant class. His posthumous name is Han Gao Zu ( 漢高祖 ). Xiang Yu chose suicide over capture.