SELENGA-ORKHON, a river of Central Asia, which rises in two principal head-streams, the Selenga and the Orkhon, on the plateau of N.W.
Near the upper Orkhon was the permanent camp of Karakorum, from the 8th century down to the end of the 13th the centre of the Mongol power, especially under the sway of Jenghiz Khan and his son Ogotai or Ogdai in the 12th and 13th centuries.
In East Siberia the Buriats occupy the Selenga and the Uda, parts of Nerchinsk, and the steppes between Irkutsk and the upper Lena, as also the Baikal Mountains and the island of Orkhon; they support themselves chiefly by live-stock breeding, but some, especially in Irkutsk, are agriculturists.
It is also very probable that the Tannu-ola Mountains north-east of Ubsa-nor8222; and the Khangai Mountains between Ulyasutai and the upper Orkhon, both running W.N.W.
"the Selenga receives the Orkhon, at the head of which remarkable inscriptions were discovered in the end of the 19th century, and cleverly deciphered.
ORKHON INSCRIPTIONS, ancient Turkish inscriptions of the 8th century A.D., discovered near the river Orkhon to the south of Lake Baikal in 1889.
A series of expeditions (of Aspelin, Snellman and Heikel) were consequently directed to those regions, especially since the discovery by Yadrintseff of the remarkable Orkhon inscriptions (see I'vIONGOLIA), which finally enabled the Danish linguist, V.
The system is pierced by the Bel-kem or upper Yenisei, and in 1 06°, at its eastern extremity, it terminates above the depression of the Selenga-Orkhon valley.