By the 13th century BC, Shang influence had reached what is now Gansu Province, a region that was occupied by a people known as the Zhou. King Wen of Zhou , the ruler of the Zhou, who was a Shang vassal, was given the title "Count of the West" by the King Di Xin of Shang . Di Xin used Duke Wen to guard his rear while he was involved in a south-eastern campaign.
Eventually Di Xin, fearing Duke Wen's growing power, imprisoned him. Although Wen was later released, the tension between Shang and Zhou grew. Wen prepared his army, and conquered a few smaller loyal states to Shang, slowly weakening Shang's allies. However, Duke Wen died in 1050 BC before Zhou's actual offense against Shang.
Di Xin paid very little attention to these, as he viewed himself as the rightful ruler of China, a position appointed by the heavens.
Duke Wen's son Duke Wu led the Zhou in a revolt a few years later. The reason for this delay was because Duke Wu believed that the "heavenly order" to conquer Shang had not been given.
Chinese civilians greatly supported Ji's rebellion. In legend, Di Xin, initially, had been a good ruler. But after he married Daji, he became a ruthless ruler. Many called for the end of the Shang Dynasty.
Duke Wu of Zhou led an army of about 50,000. Di Xin's army was at war in the east, but he still had about 530,000 men to defend the capital city of . But to further secure his victory, he gave weapons to about 130,000 slaves to protect the capital. The slaves did not want to fight for the corrupted Shang Dynasty, and defected to the Zhou army instead.
This event greatly lowered the morale of the Shang troops. When engaged, many Shang soldiers did not fight and held their spears upside down, as a sign that they no longer wanted to fight for the corrupted Shang. Some Shang soldiers joined the Zhou side altogether.
Still, many loyal Shang troops fought on, and a very bloody battle followed. The Zhou troops were much better trained, and their morale was high. In one of the Chariot charges, Duke Wu broke through the Shang 's defense line. Di Xin was forced to flee to his palace, and the remaining Shang troops fell into further chaos. The Zhou were victorious and showed little mercy to the defeated Shang, shedding enough blood "to float a log".
After the battle Di Xin placed many valuable jewelry on himself, and lighted a fire and burned himself to death in his palace. Duke Wu personally killed Daji after he found her. Shang officials were released without charges, and some later worked as Zhou officials. The imperial rice storage was opened right after the battle, to feed the starving population.
This Battle leaves Duke Wu as master of all of Shang's important cities. Duke Wu proclaimed the Zhou dynasty as King Wu of Zhou.