King Wen of Zhou
King Wu's ancestral name was Ji () and given name Fa (). He was the second son of King Wen of Zhou and Queen Taisi. In most accounts, his older brother Bo Yikao was said to have predeceased his father, typically at the hands of King Zhou, the last king of the Shang dynasty; in the "Book of Rites", however, it is assumed that his inheritance represented an older tradition among the Zhou of passing over the eldest son. (Fa's grandfather Jili had likewise inherited Zhou despite two older brothers.)