In the following periods of the Han dynasty (206 BC–220 AD), the Sui dynasty (581–618 AD), and northern dynasties (420–589 AD), the Great Wall was fixed, rebuilt, and expanded upon. Once again, the cost of lives was great, but they saw it as essential in order to keep northern invaders out of the empire. However, in the Tang (618–907 AD) and Song (960–1279 AD) dynasties, not much was done to defend against attacks in the north, and further work on the Great Wall was not put much attention to. As a side note, the Liao (907-1125 AD), Jin (1115-1234 AD), and Yuan (1271–1368 AD) dynasties built walls north of the Great Wall in Inner Mongolia and Mongolia (Waldron, Arthur).

The Great Wall’s construction started as a unification project from the Qin dynasty and ended with the last imperial dynasty of China, and with Mongolia finally under control. Perhaps millions of lives were given to its foundation, construction, and maintenance. Hundreds of battles and several wars were waged around and within its borders. The Wall stretches not only through land, but also through the many dynasties of the ever-developing China.

It was not until the Ming dynasty in the 14th century that the Great Wall truly flourished, though. When the Ming dynasty suffered a defeat by the Oirats at the Battle of Tumu, and the Ming could not push the Mongolian threat after many attacks, they decided to build a new part of the Great Wall in the north in the Ordos Desert (Karnow, Mooney et al.). The Ming also went for stronger construction materials, such as bricks and stone compared to mostly earth. In addition, there were about 25,000 watchtowers along this portion of the Wall in order to make sure the Mongols could not further their aggression in the empire (Szabó, József et al.). With some Mongolian attacks happening now and then, the Wall was continually being reinforced. Military general Qi Jiguang repaired and reinforced the north side of the Wall, and made an additional 1,200 watchtowers all the way from Shanhaiguan Pass to Changping (Great Wall of China).

Though the Mongols were a major threat to the empire from its beginnings, in the Ming dynasty, the Manchu were also gaining ground. They are an ethnic minority of China, and they began to try to seize control of Ming power around 1600. With successive battles, the Manchu overcame the Great Wall in 1644 to conquer land with the help of Li Zicheng—a rebel leader against the Ming dynasty. But as the Manchus approached Beijing, the Ming dynasty made a truce with them, and both of the armies together easily dispatched Li Zicheng’s rebels. From this intense event, the Qing dynasty was formed (1636–1912 AD) and was the last imperial dynasty of China. With the power of the Manchu on their side and renewed unity, China’s borders soon went beyond the Great Wall and Mongolia was eventually annexed. When this occurred, the further construction of the Wall came to a halt (Elliott, Mark C.).