From Gorkhapedia, the free Gorkha Encyclopedia that anyone can edit
Limbu tribe and clans belong to the Kirati nation or Kirat confederation that includes the Rai and Sunuwar who are believed to be the descendants of the ancient Mongolian people and are still known as "Mongolians" in Nepal. The name Limbu is an exonym of uncertain origin. Anyhow the word Limbu roughly means or translates as an archer or 'the bearer of bows and arrows'. They call themselves Yakthumba/Yakthung (in Limbu language). They are also known as Shong, Xong or Drenjongka (in Tibet) or Chong, Tsong in (Sikkim). Their approx population of 700,000 is centered on the districts of Sankhuwasabha, Tehrathum, Dhankuta, Taplejung, Morang, Sunsari, Jhapa, Panchthar and Ilam, all within the Mechi and Kosi zones in Nepal, also known as Limbuwan, as well as the East and West districts of Sikkim. A smaller number are scattered throughout the cities of Darjeeling and Kalimpong in West Bengal, India and also in North and South Sikkim and Bhutan.
Limbu Clans and Tribes are divided into the Lhasa gotra (those from Lhasa,Tibet) and Yunan gotra (those who come from Yunan China). The Limbu are known as des limbu (ten Limbu), even though there are actually thirteen Limbu sub-groups. Legend says that five of the groups came from Yunnan, China and the other eight from Lhasa, Tibet. There is no social discrimination among the Limbu sub-groups, although there are a number of different clans and sects.
The Chinese text called Po-ou-Yeo-Jing translated in 308 AD refers to the Yi-ti-Sai (barbarians bordering on the north), a name which is an exact equivalent of Kiratas.