Kherlen River in the context of "Keraite"

The Keraites (also Kerait, Kereit, Khereid, Kazakh: керейт; Kyrgyz: керей; Mongolian: ᠬᠡᠷᠢᠶᠡᠳ, Хэрэйд; Nogai: Кереит; Uzbek: Kerait; Chinese: 克烈, Persian: کرایت) were one of the five dominant Turco-Mongol tribal confederations (khanates) in the Altai-Sayan region during the 12th century. They had converted to the Church of the East (Nestorianism) in the early 11th century and are one of the possible sources of the European Prester John legend.

Their original territory was expansive, corresponding to much of what is now Mongolia. Vasily Bartold (1913) located them along the upper Onon and Kherlen rivers and along the Tuul river. They were defeated by Genghis Khan in 1203 and became influential in the rise of the Mongol Empire, and were gradually absorbed into the succeeding Mongol khanates during the 13th century.

The Secret History of the Mongols is the oldest surviving literary work in the Mongolic languages. Written for the Mongol royal family some time after the death of Genghis Khan in 1227, it recounts his life and conquests, and partially the reign of his successor Ögedei Khan.

The author is unknown and wrote in the Middle Mongol language using Mongolian script. The date of the text is uncertain, but the colophon to the text describes the book as having been finished in the Year of the Mouse, on the banks of the Kherlen River at Khodoe Aral, corresponding to an earliest possible figure of 1228.

Khamag Mongol (Mongolian: ᠬᠠᠮᠤᠭ
ᠮᠣᠩᠭᠣᠯ Хамаг Монгол, lit. 'Whole Mongol'; Chinese: 蒙兀國) was a loose Mongolic tribal confederation on the Mongolian Plateau in the 12th century. It is sometimes considered to be a predecessor state to the Mongol Empire.

The existence of a somewhat mysterious tribal power known in Mongol tradition as Khamag Mongol Uls is recorded in sources of the Khitan-led Liao dynasty. After the fall of the Liao dynasty in 1125, the Khamag Mongols began to play an important role on the Mongolian plains. They occupied one of the most fertile lands of the country, the basins of the river Onon, Kherlen and Tuul Rivers in the Khentii Mountains. The Taichiud (Cyrillic: Тайчууд) was one of the three core tribes in the Khamag Mongol Khanate of Mongolia during the 12th century and whose people lived in the southern part of Siberia's modern-day Zabaykalsky Krai. The present-day Zabaykalsky Krai and the Khentii Province of Mongolia were the core regions of the Khamag Mongol Khanate. The Khamags consisted of the three core clans Khiyad, Taichuud, and Jalairs.