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Secrets of the Han Wall
 The Wall constructed in the Han Dynasty (206 BC - 220) was more massive than that in the Qin Dynasty. The Han emperors not only reinforced the Qin Wall, but also extended it from Linzhao to the west part of China where much of the terrain is deserts. This presented a new challenge: how to build a wall through the Gobi Desert? Unlike the construction during the Qin Dynasty, on the plain and in the Gobi region moats formed the main fortification. Along these moats at intervals of 1.25 kilometers, a beacon tower was built. In some regions, the mountains and rivers also served as barriers so no wall or moat was necessary but towers and castles were built in key points to ensure the continuity of the defences.
 The poor quality of the sandy soil and the lack of bricks and stone give rise to the question, 'how could these towers be built in the arid Gobi Desert?' Some ruins of beacon towers in Dunhuang give us the answer. First, the workers laid a bed of red willow reeds and twigs at the bottom of a wooden frame. Then, they filled the frame with a mixture of water and fine gravel, which was tamped solid. When the mixture had thoroughly dried, the wooden frame was removed, leaving behind a solid slab of tamped earth, strengthened by the willow reeds just as modern concrete is reinforced by steel rods.
The beacon towers were constructed along the Wall at an interval of 15 to 30 miles. Columns of smoke were used to warn defenders of an attack. One smoke column meant an outpost was being threatened by a force of fewer than 500 troops and two columns meant an attacking force of fewer than 3,000. The Han found the beacon system relayed messages faster than a rider on a horse. Due to the dry climate, today in Dunhuang, you can also see the remains of these towers and even the firewood used to light the smoke.
 Han Dynasty was divided into two historical periods: Western Han (202BC-24AD) and Eastern Han (25AD-220AD). The capital of Western Han was at present Xian of Shaanxi Province and the capital of Eastern Han was at present Luoyang City of Henan Province.
Liu Bang (256BC-195BC) took the title of Han Gaozu, the first emperor of Han Dynasty (202BC-220AD), when he ascended the throne after defeating Xiang Yu in 202BC. That was right after the brief Qin Dynasty, which had imposed a centralized government on China. But the new nation was no match for the fierce Huns, who had constantly invaded its northern borders. Early Han administrators had no choice but sued for peace, and sent Chinese princesses north as Hun nobles' brides.
By 140 BC, under Liu Che (156BC-87BC), the emperor Han Wudi brought war home to the Huns. He also had several parts of the Great Wall built.
Han Wudi ordered a construction project of the Great Wall in 127 BC. This resulted in rebuilding an older part of the Wall and an extension of territories to present day Mount Yinshan of Inner Mongolia.
Huo Qubing, Emperor Han Wudi's general pushed the Huns back and in 121 BC he secured the Hexi Corridor, the passage to the Western Region. A subsequent Hexi wall construction from present day Yongdeng County to Jiuquan City in Gansu Province had severed contacts between Huns and their allies the Qiang People. The newer wall had joined the eastern terminus of an older network of walls.
Forts dotted the distance between Jiuquan City and Yumenguan Pass of Gansu Province that were also the form of the Great Wall. These were measures against Hun warlords around 110 BC. Around 101 BC Chinese workers built the section from Yumenguan Pass to Luobu Po of Xinjiang Ugyur Autonomous Region. Altogether Han Wudi had built a thousand kilometers (621 miles) of defense wall over twenty years to secure the passage to the Western Region. The Huns power later was in decline and consequently less wall-building activity came about this side of the border.
During the period of Eastern Han, after years of civil wars, Liu Xiu (6BC-57AD), the emperor Guang Wudi could put up only weak resistance to northern invaders. In around 39 AD he gave order to his general Ma Cheng to build four boundary walls to contain the damage. The boundary walls ran 1) from Lishi County of Shanxi Province to southeast of Xianyang City of Shaanxi Province; 2) between Gaoling County of Shaanxi and Anyi County of Shanxi; 3) from Taiyuan City of Shanxi to Jingxing County of Hebei Province; and 4) from Dingxian County of Hebei to Linhang County of Henan Province.
The walls offered some protection to Luoyang, the capital of Eastern Han. Afterwards in-fighting divided the Huns into the North and South. The North Huns were driven off by Han. The more friendly South Huns co-existed with the Han Dynasty and there was no need to build more walls. |
