Kirat refers to the Kirati group or a Kirata confederation that includes the Rai, Limbu, Yakkha and Sunuwar ethnic groups of Nepal. They were the earliest inhabitants of Nepal. Dhimal, Hayu, Koch , Thami, Chepang, and Surel ethnic groups also consider themselves to be of Kirati descent. In their tradition, they claim migrating from China(Yunnan) (via North Burma and Assam) and settling in Nepal.
Kirat Limbu people believe in Supreme God Tagera Ningwaphuma, who is also known as the supreme knowledge . Ancestor Yuma Sammang and God of War Theba Sammang are second most important deities.
Though all Kirat are of the Kirat religion some were in time converted to hinduism by the ruling elites of later days Nepal
There is a giant Linga of the Kirat at Kirataeshvara. It possibly had a kirat name but all such evidence was destroyed by the next rulers of Nepal
There is a tradition amongst the Kirat Limbus there the reclining Vishnu found at Budhanilakantha is the ancestor of the Limbus.
In Yoga Vasistha 1.15.5 Rama speaks of "kirAteneva vAgurA", "a trap [laid] by Kiratas", so about BCE Xth Century, they were thought of as jungle trappers, the ones who dug pits to capture roving deer. The same text also speaks of King Suraghu, the head of the Kiratas who is a friend of the Persian King, Parigha.
Hindu myth has many incidents where their God Shiva has imitated a Kirat person.
History of Limbuwan describes some of the achievements of Kirata people in eastern Nepal.
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 Rai, Limbu, Yakha and Lepcha. In ancient times, the entire Himalayan region was known as the kimpurusha desha, 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 is 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.This Kirat population in the valley, along with original Austro-asiatic and mongoloid settlers form the base for later Newar population. As time passed, however, those Kirat, now known as the Limbu settled mostly in the Koshi region of present-day eastern Nepal and Sikkim.
From around the 8th century, areas on the northern frontier of the Kirat region began to fall under the domination of migrant people of Tibetan origin. This flux of migration brought about the domination by Tibetan religious and cultural practices over ancient Kirat traditions. This influence first imposed shamanistic Bön practices, which in turn were later replaced by the oldest form of Tibetan Buddhism. The early influx of Bön culture to the peripheral Himalayan regions occurred only after the advent of the Nyingma, the oldest Buddhist order in Lhasa and Central Tibet, which led followers of the older religion to flee to the Kirat areas for survival. The Tibetan cultural influx ultimately laid the foundation for a Tibetan politico-religious order in the Kirat regions, and this led to the emergence of two major Tibetan Buddhist dynasties: in Sikkim and Bhutan. The early political order of the Kingdom of Bhutan had been established under the political and spiritual leadership of the lama Zhabs-drung Ngawang Namgyal. Consequently, Bhutan used to be known in the Himalayan region as the ‘kingdom of [Buddhist] spiritual rule’ (in old Nepali, dharmaako desh). The Tibetan rulers of Sikkim were also known as Chögyal, or spiritual rulers.
Both of these kingdoms adopted policies of suppression of indigenous practices, replacing them with those of Tibetan Buddhism. Bhutan’s religious rulers established a tradition of appointing religious missions to other Himalayan kingdoms and areas, through which they were able to establish extensive influence in the region. Bhutan’s ambitious missions were sent as far west as Ladakh. Even before the founding of modern Nepal by Prithvi Narayan Shah of Gorkha in 1769, Bhutan’s rulers were able to establish spiritual centres in several parts of what was to become the former's territories, including Kathmandu, Bhaktapur, Gorkha and Vijayapur in the midhills, and Mustang, north of the central Himalayan range.
Sikkim had long been home to Lepcha Kirat people and culture. Under the guidance of Tibetan Buddhist lamas, however, their self-rule and cultural independence was suddenly taken away. Sikkim kings were even able to subdue the entire far-eastern part of the Kirat region – historically known as Limbuwan – for at least a short period of time. Here, the new rulers adopted policies of religious and cultural subjugation, encouraging Sikkim lamas to travel to places of strategic importance in order to establish monastic centres. But the indigenous population did not easily surrender themselves to this cultural invasion. Limbu and Lepcha manuscripts collected by Brian Houghton Hodgson in Darjeeling indicate significant resistance by the Kirat against Tibetan Buddhist rule and cultural domination. While much of this struggle consisted of attempts to strengthen cultural awareness, there were also violent engagements between Kirat communities and their new rulers.
The root of this state of conflict can be seen to lie in the politics of culture and knowledge at play in the region. Sikkimi Tibetan rulers and Buddhist spiritual leaders were able to subjugate the entire far-eastern Kirat region by means of their hold over the established learned traditions and the systematic spiritual culture of Buddhism. It was realisation of this that led Sirijanga to emphasise the necessity of a peaceful, knowledge-based movement. In present-day terms, Sirijanga’s ethnic movement can be said to be one of Kirat empowerment through education. Sirijanga’s movement came to represent a significant threat in particular to the Sikkimi Bhotiya rulers and their spiritual gurus. The man’s writings and teachings, his Kirati alphabet and the literary texts he collected, attracted significant numbers of Limbus and Lepchas, and led to the start of an ethnic awakening. Sirijanga was able to establish centres of Kirat cultural and religious learning in many places throughout the eastern Himalayan hills. The Sikkimi authorities felt enough under threat to want Sirijanga eliminated. He was killed in 1741, somewhere near the Pemiyongchi Monastery in Sikkim. The Kirat learning centres were subsequently destroyed, and Sirijanga’s disciples murdered or brutally suppressed.
The next phase of military and cultural threat faced by the Kirat people was at the hands of the Gorkhali expansionists of Nepal, shortly after Sirijanga's death. The nature and intensity of this hegemony was to prove significantly different from that of the earlier Tibetan one, however. From the very beginning, the Gorkha court’s intention in the region was not the extension of its Hindu-based culture. Rather, Gorkha’s was a clear military campaign of territorial expansion.
After the completion of the conquest of the Kathmandu Valley in 1769, the Gorkhali army marched east towards the Kirat territory. The Sen rulers of eastern Nepal, known as Hindupati, had established a weak rule in the Kirat region by adopting a policy of mutual understanding with the local Kirat leaders. The Gorkhali military campaign, in contrast, brought with it a forceful and brutal occupation. During the conquest, the invading authorities adopted a harsh divide-and-rule policy: they first asked the Kiratis to surrender, assuring them that they would retain local rule and their traditional order. After many took up this offer, however, the conquerors instead demanded that Gorkhali rule be obeyed and Gorkhali traditions be followed. Manuscripts in Hodgson’s collection make mention of Kirat men, male children and pregnant women having been murdered in great numbers. The Gorkhalis ultimately divided the Kiratis into two groups, the sampriti and the niti: the former were those who had surrendered to Gorkhali power and cultural traditions, while the latter maintained their own traditions. The Gorkhali authorities naturally favoured the sampritis, killing the nitis or forcing them to flee their lands. As a result, much of the niti population migrated towards Sikkim and Bhutan. But Gorkhali wartime policy changed, particularly after the conquest of the territories of Kumaun and Garhwal far in the west. By the end of the 18th century, the authorities in Kathmandu were in need of more state revenue, and implemented a policy to bring people into Nepali territory in order to make barren land arable. The Kirat who were ousted from their lands during the Gorkhali military conquest were also asked to return home, albeit under the condition that Gorkhali rule and traditions were strictly followed. Relatives and friends of those who had fled were recruited to call them back, and people moved again between the state-given identities of niti and sampriti.