Historical legends about "Sheboye" have it that its first leader, Nyatri Tsampo, also forefather of the Tubo kingdom, came from heaven.

Nyatri Tsampo descended upon a mountaintop called Sacred Mountain Yalashangbo, where he was greeted by a group of Tibetans. Rejoicing in their good fortune, these people raised him upon their shoulders and carried him off to be their ruler. And thus he became known as Nyatri Tsampo, which means "Neck-Enthroned King" in Tibetan.

Records from the Bon religion upheld the belief that Nyatri Tsampo migrated from Bormi to Qoingye, and later became the leader of the tribe. As he was from Bormi, hence the name of the tribe he took control of was called "Sheboye" (the king from Bormi in Tibetan).

In the time of Nyatri Tsampo, the Palace of Yongbo Lhakang was established in the deep valley of the Yarlung River, which showed that, at that time, relative advanced agriculture and animal husbandry had developed there.

Later, Zhigum Tsampo succeeded Nyatri Tsampo, but Armodaze, the chief of a sub-tribe, later killed him during tribal struggles. The two sons of Zhigum Tsampo were expelled to Gongbo. One son, Nyaqi, later became the king of Gongbo. The other, Shaqi, raised an army and took revenge on Armodaze, capturing the throne and changing his title to Pude Gumgya. He also built a mausoleum for his father and constructed the castle of Qoingye, which was called Qoinwadaze. According to the record of the Annals of Tibetan Kings by Soinam Gyaincain of the Sagya Sect, during the reign of Pude Gungyal, people had the ability to make charcoal, smelt bronze, steel, silver, and other meatals; they could also construct channels to irrigate the fields. In addition, the plough and yoke appeared, and two-ox yokes were widely used at that time. With the use of iron-made tools and animal power in farming, agricultural productive forces greatly increased and the population grew rapidly, leading to the flourishing of the tribes. With the development of the tribal unions, the power of their leaders became stronger.