Selenga River
In the spring, the Asiatic Cavalry Division was divided into two brigades: one under the command of Lieutenant General Ungern and the second under Major General Rezukhin. In May, Rezukhin's brigade launched a raid beyond the Russian border, west of the Selenga River. Ungern's brigade left Urga and slowly moved to the Russian town of Troitskosavsk (present-day Kyakhta in Buryatia).