I have recently been doing some research on the Mennonites in the USSR. This religious minority among the Russian-Germans constitutes an absolutely fascinating ethno-confessional group. Although less than ten percent of the Russian-German population of the USSR there is a disproportionately large amount of material on the group both in German and in English. Much of this latter scholarship comes from Canada where many Mennonites from the Russian Empire and USSR settled. Other Russian-German Mennonite communities established themselves in the US and various Latin American countries. There are significant Russian-German Mennonite settlements for instance in Mexico and Paraguay. Their self imposed separation from their host societies has allowed them to maintain their unique culture and communal autonomy in many instances. Hence the Mennonite villages in Mexico and elsewhere still speak dialects of low German and maintain customs that have not changed in centuries. Few other diasporas have managed to retain so much of their original culture over such a long period of time.
The first Mennonite settlers in the Russian Empire came in 1789 from the region around Danzig. The next wave in 1803 also came from the Vistula. The Mennonites arriving in the Russian Empire established communities based upon their unique religion and way of life. Mennonite religious beliefs included a strong commitment to pacifism, voluntary adult baptism, a priesthood of all believers and living every day according to the example set by Christ. Their separate villages allowed them to maintain their religious based communities into the 20th century. Economically many of these settlements became relatively prosperous compared to the Russian and Ukrainian villages around them. In the late 19th and early 20th centuries, Russian-German Mennonite settlements spread from Ukraine and the Volga to North America, South America, Siberia, Kazakhstan and Central Asia. Mennonite settlements even appeared in the Khanate of Khiva, a protectorate of Tsarist Russia in Central Asia, during the late 19th century. The Mennonites established religious centered communities isolated from the surrounding population in all these new locations.
Due to their rejection of most interaction with the secular world including a refusal to serve in the military and swear oaths to the state, they came under particularly strong pressure from the Soviet government. Even more so than other confessional groups among the Russian-Germans, the Mennonites suffered horrible losses at the hands of the communists. As a result of the 1941 deportations, special settlement regime and labor army an excess of 250,000 Russian-Germans or about 20% of their population in the USSR perished during the 1940s. Other estimates put the number at 300,000 or 25%. There is general agreement that the Mennonites lost a greater portion of their population than other Russian-Germans due to these causes. Out of 100,000 Mennonites some 30,000 or 30% perished as a result. This is a loss equal on a per capita basis with that Hitler inflicted upon the world's Jewish population.
In the summer and fall of 1941, the Stalin regime forcibly deported some 28,000 Mennonites from Crimea, the Volga, Ukraine and Caucasus to special settlements in Kazakhstan and Siberia. Some 35,000 managed to avoid deportation due to the rapid advance of the German military. Another 27,000 Mennonites in the Urals, Siberia, Kazakhstan and Central Asia found themselves conscripted into the labor army. Out of the 35,000 that initially avoided deportation, the Allies forcibly repatriated 23,000 back to the Soviet Union. Only around 12,000 managed to avoid this fate. They later immigrated to Canada and Paraguay. The remainder of the Mennonite population of the USSR remained confined to its Asian regions.
In the post-Stalin period, the Mennonites remained subject to considerable persecution on the basis of both their religion and being German by nationality. The Mennonite Brethern remained an outlawed religious denomination until 1967. Even after legalization they continued to suffer from signficant restrictions on their religious practices. Continuing persecution convinced the Mennonites like it did all other Russian-Germans that they had no future in the Soviet Union. After 1987, most of the Mennonite population of the USSR left to settle in Germany. In this matter they did not differ from the Lutheran majority or the substantial Catholic minority among the Russian-Germans. The once self-contained Mennonite villages speaking Plautdiitsch in Siberia, Kazakhstan and Central Asia have largely evaporated.