Prithvi Narayan Shah, insatiable in his desire for fresh conquests, sent an army towards the east, in order to invade the country of the Kirantis, even menacing Sikkim.
The Kiratas colonized the valley of eastern Nepal, North Videya, in sub Himalayan region after having conquered it and set up a dynastic rule in pre-Christian era in succession to the Abhiras, and ruled for about 29 generations from 400 B.C to 700 A.D. Their first Chieften (king) was Yalamber (Yalambara, Yellung or Yalambhang ) and their Kingdom extended from river Trisuli in the west to the river Tista in the east.
There are different festivals in Kirat religion. They are namely chawamang, mangpuja, chhonglak, maghe sakranti (New Year), udhauli puja (sakela), ubhauli puja (sakela) and sime bhume puja.
A typical Rai house is built with wooden planks/logs, half walled and having open space in the front. Earlier they used to have thatched roof which has largely been replaced by the tin roof in recent years.
Sakela is the cultural dance and festival of Kirat Rai. Dancing Sakela, the Suptums are prayed to save the crops. Sakela starts when the Nakshong (a Rai priest) offers Raksi (liquor made from fermented rice) from Chindo sprinkling around the Sakela Thaan (place where Sakela is established).