For over two millennia, a large portion of the eastern Himalaya has been identified as the home of the Kirat people, of which the majority are known today as Limbu, Sunuwar, Rai,and Yakkha. In ancient times, the entire Himalayan region was known as the Kimpurusha Desha (also, Kirata Pradesh), a phrase derived from a Sanskrit term used to identify people of Kirat origin. These people were also known as Nep, to which the name Nepala and Newar are believed to have an etymological link. The earliest references to the Kirat as principal inhabitants of the Himalayan region are found in the texts of Atharvashirsha and Mahabharata, believed to date to before the 9th century BC. For over a millennium, the Kirat had also inhabited the Kathmandu Valley, where they installed their own ruling dynasty. According to the history of Nepal, the Kirats ruled for about 1225 years (800 BCE–300 CE), their reign had a total of 29 kings during that time.
The Himalayan Kirat people practice Kiratism, calling it “Kirat religion”. The Kiratis follow Kirat Mundhum. Their holy text is the Mundhum, also known as the Kirat Veda. Kirati people worship nature and their ancestors. Animism and shamanism and belief in their primeval ancestors, (Sumnima/Paruhang)and (Yuma Sammang) are their cultural and religious practices. The names of some of their festivals are Sakela, Chasok Tangnam, Sakle, Tashi, Sakewa, Saleladi Bhunmidev, Chyabrung, Yokwa and Folsyandar. They have two main festivals: Sakela/Sakewa Ubhauli during planting season and Sakela/Sakewa Udhauli during the time of harvest. Khas Kiratis and Tibetan-Himalayan or Sikkimese follows Buddhism and the Kacharis of Northeast, India follows the Bathouism religion, named after Bathou which in Bodo means the five principles. The five principles are: bar (air), san (sun), ha (earth), or (fire) and okhrang (sky). The chief deity, called Bathoubwrai (bwarai: “the Elder”)—omnipresent, omniscient and omnipotent—is said to have created the five principles. Though there are other minor gods and goddesses, Bathoubwrai is considered the Supreme God. The second most important deity is Mainao, the consort of Bathoubwrai, who is considered as the “protector of the rice fields”. Some ethnic groups also have adopted Christianity and Hinduism religion cause of mixing up with Indian nation.
Kirat Limbu people believe in a supreme god called Tagera Ningwaphuma, Yuma Sammang who is also known as the supreme knowledge. The Kirat ancestor Yuma Sammang and god of war Theba Sammang are the second most important deities.
Kirat mainly believe in Shiva, the Hindu lord. There is a giant linga of the Kirat at Kirateshwara