when was the great wall of china done
212 BC
title: History of the Great Wall of China text: History of the Great Wall of China The history of the Great Wall of China began when fortifications built by various states during the Spring and Autumn (771–476) and Warring States periods (475–221) were connected by the first emperor of China, Qin Shi Huang, to protect his newly founded Qin dynasty (221–206) against incursions by nomads from Inner Asia. The walls were built of rammed earth, constructed using forced labour, and by 212 ran from Gansu to the coast of southern Manchuria. Later dynasties adopted different policies towards northern frontier defense. The Han (202 – 220), the Northern Qi (550–574), title: Great Wall of China text: Great Wall of China The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China to protect the Chinese states and empires against the raids and invasions of the various nomadic groups of the Eurasian Steppe with an eye to expansion. Several walls were being built as early as the 7th century BC; these, later joined together and made bigger and stronger, are collectively referred to as the Great Wall. Especially famous is the wall built in 220–206 title: History of the Great Wall of China text: agreed upon as an acceptable compromise the 1470s. Yu Zijun (余子俊; 14291489) first proposed constructing a wall in the Ordos region in August 1471, but not until 20December 1472 did the court and emperor approve the plan. The 1473 victory in the Battle of Red Salt Lake (紅鹽池) by Wang Yue (王越) deterred Mongol invasions long enough for Yu Zijun to complete his wall project in 1474. This wall, a combined effort between Yu Zijun and Wang Yue, stretched from present day Hengcheng (橫城) in Lingwu (northwestern Ningxia province) to Huamachi town (花馬池鎮) in Yanchi County, and from there to title: Great Wall of China text: There are no surviving historical records indicating the exact length and course of the Qin walls. Most of the ancient walls have eroded away over the centuries, and very few sections remain today. The human cost of the construction is unknown, but it has been estimated by some authors that hundreds of thousands, if not up to a million, workers died building the Qin wall. Later, the Han, the Sui, and the Northern dynasties all repaired, rebuilt, or expanded sections of the Great Wall at great cost to defend themselves against northern invaders. The Tang and Song dynasties did not title: History of the Great Wall of China text: north of Nong'an County to the banks of the Songhua River. When the Jurchens, once Liao vassals, rose up to overthrow their masters and established the Jin dynasty, they continued Liao's wall-building activities with extensive work begun before 1138. Further wall construction took place in 1165 and 1181 under the Jin Emperor Shizhong, and later from 1192 to 1203 during the reign of his successor Emperor Zhangzong. This long period of wall-building burdened the populace and provoked controversy. Sometime between 1190 and 1196, during Zhangzong's reign, the high official Zhang Wangong (張萬公) and the Censorate recommended that work on the