According to Wikipedia: Baikal Cossacks were Cossacks of the Transbaikal Cossack Host (Russian: Забайка́льское каза́чье во́йско); a Cossack host formed in 1851 in the areas beyond Lake Baikal (hence, Transbaikal). Organisation The Transbaikal Cossack Host was one of those created during the 19th century as the Russian Empire expanded to the Far East and South-East. It remained smaller than the Don Cossacks and other longer-established Hosts. The Transbaikal Cossack Host partially consisted of Siberian Cossaks, Buryats, Evenk (Tungus) military units, and included the peasant population of some of the regions. The military component included three cavalry regiments and three unmounted brigades. Its main purpose was to patrol the Sino-Russian border and perform everyday military duties in the region.