Ji Chang was the king of Zhou, a tributary state in the Shang Dynasty, commonly referred to as King Wenwang of Zhou. A suspicious tyrant, King Zhouwang, the last sovereign of the Shang, who reigned from 1075 to 1046 BC, feared that the regional lords with large numbers of troops under their control could pose a threat to him. He lured Ji Chang and other kings to Chaoge (today's Qixian County, northern Henan Province), a secondary capital of Zhouwang, and imprisoned them.
Boyikao, Ji Chang's son, went to rescue his father but was killed in Chaoge. Heartbroken, his younger brother Ji Fa was determined to quickly rescue his father by any means. He finally succeeded after bribing Zhouwang with many treasures and pretty young women, while humbly pleading with him. Thus his father was saved. Later, Ji Fa became the first monarch of the Western Zhou Dynasty - King Wuwang.
Returning home, mindful of his son's death and the cruelty of Zhouwang, King Wenwang resolved to practice good governance in his state to improve it, biding the time when it could be powerful enough to topple the tyrant. However, he lacked a good aide competent in both civil administration and military tactics.
One night, he dreamt of the Heavenly God with a white-haired, white-bearded old man. "Allow me to bestow a good teacher and aide to you," the Heavenly God said to him. "His name is Wang." As he and the old man fell down on their knees to thank the Heavenly God, he woke up.