At Irkutsk and in the valley of the Irkut the admixture of Tungus and Buriat blood is obvious, and still more in the Nerchinsk district and among the Transbaikal Cossacks settled on the Argun.
Here Tungus diggers were encountered who had extracted handfuls of gold in small nuggets from a stream bed at a depth which they stated to be no greater than 2 ft.
In the 11th century Korea was stripped of her territory west of the Yalu by a warlike horde of Tungus stock, since which time her frontiers have been stationary.
In order to study the different eastern kinsfolk of the Finns, Sjogren (1792-1855) extended his journeys to North Russia, and Castren to West and East Siberia (Nordische Reisen and Forschungen), and collected the materials which permitted himself and Schiefner to publish grammatical works relative to the Finnish, Lappish, Zyrian, Tcheremiss, Ostiak, Samoyede, Tungus, Buryat, Karagas, Yenisei-Ostiak and Kott languages.
A theory which seems plausible is that which assumes them to have been a heterogenous collection of Mongol, Tungus, Turki and perhaps even Finnish hordes under a Mongol military caste, though the Mongolo-Tungus element probably predominated.