In the beginning of the Tang Dynasty, to crack down on the famous scholar-gentry clans of the Wei and Jin Periods, to enhance the social status of the royal families and imperial power, Emperor Taizong ordered the compilation of the Annals of the Clans (氏族志).

The scholar-gentry clans had fallen low in the Sui and Tang Dynasties, but they still boasted of their ancestry. The past famous clans such as Cui, Lu, Li, Zheng and Wang intermarried with each other and played up their nobleness. More betrothal gifts would be collected in case of marriage with ordinary clans. This kind of habit resulted in much controversy and deeply objected by Emperor Taizong. He ordered Gao Shilian, Minister of Personnel, Wei Ting, Imperial Inspector General, Cen Wenben, Deputy Head of Legislative Bureau, Ling Hude, Deputy Head of Rites and Ceremonies, and other literati familiar with clans and genealogy to seek for genealogies around the country, identify the genealogical orders and write the Annals of the Clans with reference to the history. Surname Cui, the gentry clan in Shandong, was ranked as the first class. But Emperor Taizong thought that prominence should no longer be given to the surnames of Cui, Lu, Wang and Xie after the unification of the country and the genealogical orders should be arranged according to the official ranks. According to the Emperor's opinions, the Annals of the Clans was rewritten and completed in the 12th year of the Zhenguan's Reign (638).

Total 293 surnames were collected in the Annals of the Clans, classified into 1651 families and 9 grades, thus establishing the new aristocratic family system headed by the royal family of Li and centered with the heroes of the Tang Dynasty (including traditional aristocrats and new upstarts in the now Gansu and Shaanxi Provinces), in stead of the old aristocratic system of the Southern and Northern Dynasties.