 Guanzhong dialect was once the official language of the four dynasties of Zhou, Qin, Han and Tang.The unification pattern of Han Dynasty and the great integration of nationalities promoted Xi'an dialect to influence dialects all over the country, and reached its peak in Tang Dynasty.However, the dialects spoken in northern and southern Shaanxi differ from that of Guanzhong, such as the Hanzhong dialect, which is more closely related to Sichuanese Mandarin.