Just like the similar course of other nationalities worldwide, the ancient Tibetan people combined different clans and then formed different tribes according to their blood relationship.

It also witnessed the successive appearance of the matrilineal and patriarchal communes.

The book titled Historic Collection of Tibetan and Han states that the ancestors of the Tibetan were divided into four clans named Se, Rmu, Stong and Ldong. The book also states that each clan had four branches, such as the Dbra, Vgru, Ldong,Lga, Dbas and Brdav, each further divided into many sub-branches.

In Tibetan, the English word "surname" was called "rus-pa", which literally means "bone" or "bone lineage", showing the close relationship between surname and blood relationship.

In ancient times, with the development of production, the growth of population and the migration of clans, tribes split and then merged with others in new tribes through intermarriage, forming alliances and military conquest, as subjugated tribes pledged allegiance to the winners of the incessant wars for water resources, pastureland, farmland and subjects.

At the same time, the polarization of rich and poor as well as the difference in social status came into being, as tribal leaders emerged as a noble class who handed their accumulated fortunes and powers on to their descendants. So, the big gap between "King" and "minister" as well as between "noble" and "populace" was gradually established. The captives of wars were treated as slaves and the conquered tribes offered tribute and taxes and provide sources of soldiers for further wars.

Generally speaking, tribal unions experienced incessant disintegration and recombination, with new tribes rising following the decline of old ones.