In 53 BC, crassus, Consul General of the Roman Empire, set seven legions to invade the rest (Mitya) and panicked in Calais. Crassus's eldest son, Publi Uzi, led the First Corps to break through the eastern border and move to the western regions. After years of tossing and turning, he surrendered to the Western Han Dynasty from the Xiongnu in Da Yue around 36 BC and set up Zhelai Village in Yongchang County. First, in 36 BC, the Han army was with the Huns.

Ritchie people are brave and good at fighting. He Hao, the former cool general, was defeated in the Eastern Jin Dynasty, which had a great influence on Longyou. Later, it gradually merged with the Han nationality and other ethnic groups, contributing to the unity, social progress and economic prosperity of the Chinese nation. Chen Han Chuan Tang records that in 36 BC, the Western Regions of the Han Dynasty defended Gan Yanshou and paid a captain, Chen Tang, to crusade against Xiongnu. They used the method of 100 infantry, with scales and shields, and there was a heavy wooden city outside the city. This method was only adopted by the Roman army at that time. For this reason, historians believe that this is the remnant of a Roman army that collapsed in the Battle of Calais and has disappeared 17 years. According to historical records, Li Gan County was established in the Han Dynasty at the foot of Qilian Mountain south of Yongchang County, Gansu Province. It is a record of building an ancient castle specially for this group of ancient Romans. The descendants of these Roman legions last appeared in the historical records in the Romance of the Three Kingdoms. Ma Chao led the descendants of the Roman legion renamed "Xiliangbing" to defeat Cao Cao. In the eleventh year of Emperor Wendi, in 592 AD, in view of the assimilation of Li Longren by the Han people, Emperor Wendi issued a decree to merge Li Gan County with counties and set up a county in Li Gan.