Question: Which Russian ruler and naval commander also took part in polar expeditions to study the Arctic Circle?
Sentence (from "Alexander Kolchak"): During the Russian Civil War, he established an anti-communist government in Siberia—later the Provisional All-Russian Government—and was recognised as the "Supreme Ruler and Commander-in-Chief of All Russian Land and Sea Forces" by the other leaders of the White movement from 1918 to 1920.
Relevant evidence: No