when did the great wall of china started building
221–206 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: 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 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: History of the Great Wall of China text: would be mostly followed by the later Ming wall west of Gubeikou, which includes reconstructed walls from Qi and Zhou. In more recent times, the reddish remnants of the Zhou ramparts in Hebei gave rise to the nickname "Red Wall". The Sui took power from the Northern Zhou in 581 before reuniting China in 589. Sui's founding emperor, Emperor Wen of Sui (r.581604), carried out considerable wall construction in 581 in Hebei and Shanxi to defend against Ishbara Qaghan of the Göktürks. The new walls proved insufficient in 582 when Ishbara Qaghan avoided them by riding west to raid Gansu