There is no clear conclusion as to where the founding place was found in the Kaiyuan Dynasty of Huichang with the character Ping on its back. The author temporarily assumes that the place of casting was in Pingzhou. Pingzhou belongs to Hebei Province. It was named Pingzhou in Lia

Huichang Kaiyuan is signed with the character Ping on the back. There is no clear conclusion about its founding place. The author temporarily says that the founding place is Pingzhou . Pingzhou belongs to Hebei Province. It was named Pingzhou in the late Han Dynasty and Liaodong . In the Northern Wei Dynasty, the old Pingzhou was designated as Yingzhou , and another Pingzhou was established. During the Tang Dynasty, Lulong (now Lulong County, Hebei Province) was the seat of government. The Lulong Jiedu envoy who served in Huichang for five years was Zhang Zhongwu .

Zhang Zhongwu (?-849), a native of Fanyang (southwest of today's Beijing), his ancestral home is Qinghe, and a famous general in the late Tang Dynasty. In 841, Zhang Zhongwu served as the military governor of Lulong and was granted the title of King of Lanling County. Zhang Zhongwu defeated the Uighurs, Khitans and Xi tribes. Zhang Zhongwu fought several times and made outstanding contributions to the stability of the Tang Dynasty's border. Li Jian praised Zhang Zhongwu for "breaking the Mao Huan crowd, and the account was surplus to 7,000; expanding the territory of Xianbei, opening up thousands of miles of land. Thousands of people were killed, and hundreds of barbarians surrendered."

Zhang Zhongwu served as an official to Situ, Zhongshu Menxia Pingzhang He died during the Dazhong period, and his posthumous title was Zhuang. The "Old Book of Tang Dynasty·Zhang Zhongwu Biography" commented on him: " Yuyang sudden riding, Yange vigorous, bold and brave Yuan Rong, watching the tiger with eager eyes." The story of iron-blooded loyalty and boundless heroic spirit makes me feel emotional and inspiring every time I read it.