In preparation for the peace conference that was expected to follow World War I, in the spring of 1917 the British Foreign Office established a special section responsible for preparing background information for use by British delegates to the conference. Don and Volga Basins is Number 53 in a series of more than 160 studies produced by the section, most of which were published after the conclusion of the 1919 Paris Peace Conference. The study covers the provinces of the Russian Empire at that time of Astrakhan’, Kazan, Kostroma, Nizhni-Novgorod, Samara, Simbirsk, Vladimir, Voronezh, and Yaroslavl’, as well as the territory of the Don Cossacks. It recounts the settlement of the Volga Basin in the early Middle Ages by Slavic peoples, the Tatar invasion of the 13th century, and the expansion of Russia into the region from the late-16th century onward. It notes the importance of the Don Cossacks, independent peasant-soldiers, who were subjugated by the Russians in 1623 and thenceforth served the tsars in suppressing internal revolts and defending the external frontier. The peoples of the Volga Basin included Russians, Ukrainians, Germans, Tatars, and various other smaller groups. This part of Russia also had a significant Muslim minority, and the study notes (citing the 1896 census) that 16.4 percent of the people in the Volga Basin were Muslim. World War I and the Russian Revolution increased pressures for local autonomy and led to the formation of a Tatar Republic at Kazan, which later became part of the Soviet Union.