Who were Xiang Yu and Liu Bang, the figures behind the board's river inscription?
These answers restate the rules implemented by our open-source engine, which follows the WXF laws and is regression-tested against the official 110-diagram repetition casebook. Where an answer refers to a specific position, that position lives on the linked reference page, where the build verifies it against the engine before publishing.
Direct answer
Xiang Yu, the King of Western Chu, and Liu Bang, who founded the Han dynasty, were the two rival leaders of the historical Chu-Han contention that followed the collapse of the Qin dynasty, roughly 206 to 202 BCE. Their conflict is the real historical event the board's 楚河漢界 inscription refers to, even though it says nothing about when the game itself was invented.
The historical background, briefly
After the Qin dynasty fell, Xiang Yu and Liu Bang, former allies against Qin, turned on each other for control of China. Liu Bang eventually prevailed, becoming Emperor Gaozu and founding the Han dynasty, one of the most influential in Chinese history. The struggle produced a famous, often-renegotiated boundary between the two sides' territory, which is the "border" the board's inscription names.
Why this history and the game's history are separate questions
The events themselves are real and well documented far beyond xiangqi. What is not documented is any link between this specific war and the invention of the board game; the inscription is a later decoration referencing a well-known historical episode, not evidence that the game existed at the time. See what 楚河漢界 means for how that confusion tends to arise.
Related questions
Did Xiang Yu or Liu Bang actually play xiangqi?
No source suggests it. The modern game emerged roughly a thousand years later, in the Song dynasty.
Is the Chu-Han contention itself well documented?
Yes, extensively, in classical Chinese historical records. It is one of the best-known episodes in the transition from Qin to Han.
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