In the year 550 AD, Gao Yang, a Han Chinese who had adopted Xianbei culture, became the prime minister of Eastern Wei and was granted the title of Prince of Qi, following in the footsteps of his father Gao Huan. Gao Yang, then known as Emperor Wenxuan of Qi, overthrew Eastern Wei and proclaimed himself emperor, establishing the Qi Dynasty. He adopted the reign title Tianbao and kept the capital in Ye (now southwest of Linjin, Hebei). Historians later referred to this dynasty as Northern Qi, also known as Gao Qi, to distinguish it from the Qi Dynasty established by Xiao Daocheng in the south.
After the establishment of the Northern Qi Dynasty, it inherited the territories of Eastern Wei, including Henan, Shanxi, Hebei, Shandong, and parts of Liaoning and Inner Mongolia east of Luoyang. It bordered the Southern Liang Dynasty (which became Chen after its downfall in 557 AD) to the south, connected with Western Wei (which became Northern Zhou after its downfall in 556 AD) to the west, faced the Bohai Sea to the east, and neighbored the Rouran, Khitan, Turks, and Kumoxi to the north.
On one hand, Gao Yang implemented political measures to combat corruption, enacted the Qi Code of Laws, and established administrative divisions to stabilize the internal affairs of the Northern Qi Dynasty. On the other hand, in order to strengthen defense and consolidate the border, he initiated military reforms. Over the course of 27 years, the Northern Qi Dynasty launched continuous attacks against the northern enemies, including the Rouran, Turks, and Khitan, achieving successive victories. During these military campaigns, the Northern Qi Dynasty also constructed multiple sections of the Great Wall to consolidate the northern borders and defend against the Northern Zhou. The scale of the Great Wall built by the Northern Qi Dynasty was second only to the Great Wall built during the Qin Dynasty.
The Northern Qi Dynasty built three sections of the Great Wall. The first section extended from present-day Qingshuihe County in Inner Mongolia, passed through Zhangjiakou, and reached the Shanhaiguan area where it met the sea. The second section was built to defend against the Northern Zhou, stretching from Huangluling to Juyongguan. The third section, also built to defend against the Northern Zhou Dynasty, extended from Wutai in the north to Niangziguang in the south. After the Northern Zhou unified the north, they repaired and reinforced the section of the Northern Qi Great Wall that ran from Yanmen in the west to Jieshi in the east, in order to defend against the Rouran, Khitan, and other steppe tribes.
