Lingnan refers to the area south of Wuling Mountain Range in southern China, which is equivalent to all the territories of Guangdong, Guangxi and Hainan, as well as parts of Hunan and Jiangxi provinces. Historically, Lingnan also included the Red River Delta, which was once ruled by the China Dynasty. After Vietnam became independent from China, the concept of Lingnan gradually excluded Vietnam. Due to the change of administrative divisions, when the word "Lingnan" is mentioned now, it refers to Guangdong, Guangxi and Hainan provinces, and some counties and cities south of Jiangxi and Hunan Wuling are not included. Lingnan was the land of Baiyue and the place where Baiyue people lived in ancient times. At the end of Qin Dynasty and the beginning of Han Dynasty, it was under the jurisdiction of Nanyue State. The so-called Lingnan refers to the south of the Five Ridges, which consists of five mountains: Yuechengling, Dupangling (referring to Jieyang Ridge), Zhumengling, Qitianling and Dayuling. Generally distributed in eastern Guangxi to eastern Guangdong and the junction of Hunan and Jiangxi provinces. It is the largest horizontal tectonic belt mountain range in southern China, and it is also the watershed between the Yangtze River and the Pearl River. It has been a natural barrier for a long time. The Nanling Mountains hindered the communication and economic ties between Lingnan and the Central Plains, which made Lingnan's economy and culture far inferior to that of the Central Plains, and was called "the land of barbarians" by northerners. Since Zhang Jiuling, the prime minister of the Tang Dynasty, dug the Meiguan ancient road in Dayuling, the Lingnan area has been gradually developed.