 Complete the following phrase:  Archaeological discoveries at the Sanxingdui and Jinsha Site have established that the area surrounding Chengdu was inhabited over four thousand years ago, in 1810th centuryBC. At the time of Chinas Xia, Shang, and Zhou dynasties, it represented a separate ancient bronze-wielding culture whichfollowing its partial sinificationbecame known to the Chinese as Shu. Shu was conquered by Qin in 316BC and the settlement re-founded by the Qin general Zhang Yi. A Chinese legend explains the towns nickname Turtle City by claiming Zhang planned the course of his city walls by following a turtles tracks. Although he had argued against the invasion, the settlement thrived and the additional resources from Sichuan helped enable the First Emperor of Qin 