By the 12th century BC, Shang influence extended west to the Wei River valley, a region that was occupied by clans 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 (King Zhou). Di Xin used Duke Wen to guard his rear while he was involved in a south-eastern campaign. Chinese civilians greatly supported Duke Wu'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.