Yongchang County (永昌县) is a county located in the province of Gansu in China. It belongs to the prefecture of Jinchang. The ancient North Silk Road passes through Yongchang County; numerous Han envoys were sent west along this trackway, some parties exceeding 100 members late in the first millennium BC. The Han Dynasty sent one mission to Parthia, which was reciprocated at around 100 BC: Roman emissaries were captured by the Chinese in 30 BC along the Silk Road at Yongchang.
During recent years, the county has entered the sight of media because many of the inhabitants of Liqian village (骊靬) are thought to be descendants of a Roman legion. The history records of the town indicate that it was founded by captured combatants of the Battle of Zhizhi during 36 BC. In a geography book of the eastern Han Dynasty it is recorded that "Local people call the ancestors of the Roman prisoners-of-war Lijian" the word Lijian being the Chinese name for something or someone of Greco-Roman origin. A number of the town's inhabitants still bear some features of Europeans. A DNA test was conducted in early 2007 in the attempt to find genetic evidence supporting this claim. The result of this specific study was negative. The study concluded: "Overall, a Roman mercenary origin could not be accepted as true according to paternal genetic variation, and the current Liqian population is more likely to be a subgroup of the Chinese majority Han".