In 756 AD, Tang Suzong Hengli ascended the throne in Lingzhou, Ningxia, thus establishing the Zhongxing period of the Tang Dynasty, making Lingzhou City in a corner the largest military town in the Tang Dynasty, and also the political and military center during the counter-insurgency period of the Tang Dynasty. However, due to historical changes, the exact geographical location of Guling House has been an unsolved mystery in the field of archaeology and history in China, so that lingwu city is now considered as the location of Guling House. At present, an epitaph unearthed from the tomb of Tang Dynasty in Wuzhong unveiled the mysterious veil of Guling House. According to textual research, the site of Guling Prefecture is located in the northwest of Wuzhong today.

On May 8, 2003, in the suburb of Litong District, Wuzhong City, Ningxia, two epitaphs were excavated from the tomb of Tang Dynasty, one of which was badly damaged and the handwriting was illegible.

Another epitaph: Epitaph of Mrs. Lu in Dongping County of Tang Dynasty, with clear handwriting. This epitaph is about 32 cm long, 23 cm wide and 8 cm thick. Made of red sandstone, the overall color is red, and the words 3 18 are engraved on it.

According to archaeological experts' research, the owner of this tomb is Mrs. Lu, "Lingzhou was privately owned after all, at the age of 57" and "buried in the county East Park". According to the epitaph, Mrs. Lu's father was Zuoya's military envoy in Shuofang, and her husband was a junior officer in the army. In 830 AD, that is, in the fourth year of Tang Wenzong Daiwa, Mrs. Lu died of illness at her home in Yu Ling and was buried in the East Garden of the county. Le Hui County is Lingzhou College, which is in the same city as Lingzhou. Since the tomb is in the east of Lingzhou (Le Hui County), Lingzhou (Le Hui County) must be in the west of the tomb, and the west of Wuzhong is the ancient city. The ancient city is the abbreviation of "Guling Fucheng" in the Annals of Ningxia written by Zhu Yan, the king of Qing Dynasty. There are no ancient cities near Wuzhong, including lingwu city and Yinchuan. Therefore, the discovery of the epitaph proves that Guling House is located in Wuzhong, Ningxia.

Top right: The epitaph and preface of Mrs. Lu in Dongping County of Tang Dynasty is the archaeological evidence of the Armed Forces Department of Ningxia today. On May 8, 2003, Wuzhong Greenland Park in Ningxia was unearthed.

Right: Address map of the epitaph of Mrs. Lu in Dongping County of Tang Dynasty unearthed in Wuzhong Greenland Park, Ningxia in 2003. The epitaph was found in wuzhong, which proves that Guling House is located in Wuzhong, Ningxia.

Researcher Lu, an expert in Ningxia's historical geography and the first author of Ningxia's Historical Geography Examination, pointed out:

There are three places called ancient cities in Ningxia, and now there are experts and scholars in Ningxia to verify them. The ancient city of Pengyang County is Na County in Qin and Han Dynasties, Zhongning County is Juanjuan County in Western Han Dynasty, and Wuzhong Ancient City is Gulingzhou County (Lingzhou County) in Western Han Dynasty.

Right: monographs by famous experts on history and historical geography of Ningxia: the cover of "Examination of Historical Geography of Ningxia" by Lu, Wu Zhongli and Xu Zhuang. Ningxia People's Publishing House, 1993.

Historically, Lingzhou was the political, economic and cultural center of northern China in ancient times, and Le Hui County was the seat of Guling Prefecture (formerly known as the branch office, now the so-called central city). The important discovery of epitaph has solved the long-standing problem of where Guling House is in history. Archaeologists said that with the excavation of this epitaph as a symbol, it was definitely proved that Guling House was located in Wuzhong, Ningxia, where this large Tang tomb group was discovered. (20 12.4.27

Lingzhou is once again located in the northwest of Pyongyang, North Korea.