Grand Duke Jiang, real name known as Jiang Shang, alias Zi Ya, was a founding father of Western Zhou Dynasty.

According to Records of the Grand Historian,Jiang Ziya, old and indigent, was fishing by the Wei River for days. One day he met King Wen of the Zhou Dynasty hunting by the river and had a congenial talk with him. King Wen said, "My father Taigong (Grand Duke) once predicted that Zhou will become prosperous when a saint arrives. Are you the one? He has waited too long for you to come." Therefore, King Wen honored Jiang Ziya "Taigong Wang" (expectation of the Taigong) and respected him the grand tutor, the highest official position managing both civil and military affairs. Later King Wu succeeded upon King Wen's death. Jiang Ziya helped him in overthrowing King Zhou of Shang Dynasty and founding the Zhou Dynasty. He was conferred Marquis Qi by the king.

The story remained simple in history records because of its distant history. However, there had been historical novels about it passed down among people, among which the Investiture of the Gods, a novel of gods and spirits in Ming Dynasty had a major character named Jiang Ziya. He has been commonly referred to as Grand Duke Jiang among people.