Each and every one of China’s Great Walls functioned primarily as a physical barrier to block the southerly advance of nomadic enemies on horseback.
Before unification in 221 B.C. there were a number of Changcheng (Long Walls), but it was Emperor Qin Shihuang who created the first Wanli Changcheng (Great Wall) of subcontinental scale.
After construction of the Walled Square of Chu many more ‘new era’ Long Walls were built from the late fourth century B.C..
Three very early text records provide clues on when the first changcheng, or long wall, may have begun.
Legend has it that during the Xia Dynasty (c. 2070-1600 B.C.), a sage named Gun, father of Yu the Great, built a concentric walled city in which the inner structure defended his son the prince, while the outer one protected the common people.
