A very primitive record of the ancient history of Tibet exists from around the 1st century. Forefathers of the Tibetan race passed down segments of history orally. During the Tubo Kingdom, historians began to write them into their works.
Legend has it that the Tibet Plateau was dotted with various tribal clans, which are known as the "12 small states'' or "40 small states'' in Tibetan history books. According to these books, where these small states were located there were small towns which, through repeated wars and ensuing peace, became formidable tribes. Of these large tribes, the most powerful ones included the Yarlung Tribe in the Shannan River Valley, the Zhangzhung Regime in Ngari, and the Supi Tribe north of the Yarlung Zangbo River. At that time, the Lhasa River valley was known as the "Gyiqoiko'', with present-day Lhasa calls "Gyixoiwotang'' (meaning fertile land downstream from the Gyiqoi River).
The Gyiqoi River Valley was then ruled by two princes: Dagyiwo and Chibangsum of the Supi Tribe. In the early 7th century, Nangri Songtsan, leader of the Yarlung Tribe, sent his troops northward, crossing the Yarlung Zangbo River. With the coordination of the Nang clans under the rule of Chibangsum, they seized Chibangsum to rule the whole of the Gyiqoi (Lhasa) River Valley. Namrisum had his headquarters set up at Gyiamargang in Maizhokunggar. He had several palaces built in the narrow gully, which ran from south to north. Songtsan Gambo, his son and later king of the Tubo Kingdom, was born in the Qamba Mingcholing Palace at Gyiamargang.