and Mecklenburg-Strelitz became Grand Duchies in 1815, and in 1870 they voluntarily joined the new German Empire, while retaining their own internal autonomy. After the First World War and the abdication of the German Kaiser, the monarchies of the duchies were abolished and republican governments of both Mecklenburg states were established, until the Nazi government merged the two states into a unified , a virtually meaningless administrative decision under the centralised regime. Western Pomerania Vorpommern, literally Fore-Pomerania, is the smaller, western part of the former Prussian Province of Pomerania; the eastern part became part of Poland after the end of World War II. In the Middle Ages, the area was ruled by the Pomeranian dukes as part of the Duchy of Pomerania. Pomerania was under Swedish rule after the Peace of Westphalia from 1648 until 1815 as Swedish Pomerania. Pomerania became a province of Prussia in 1815 and remained so until 1945. Mecklenburg-Vorpommern Wartime In May 1945, the armies of the Soviet Union and the Western allies met east of Schwerin. Following the Potsdam Agreement, the Western allies handed over Mecklenburg to the Soviets. Mecklenburg-West Pomerania was established on 9 July 1945, by order No. 5 of Red Army Marshal Georgy Zhukov, head of the Soviet Military Administration in Germany (SMAD), as the Province of Mecklenburg and West Pomerania (zapadnoi Pomeranii). During the war, the make-up of Mecklenburg and Vorpommern's population changed, due to wartime losses and the influx of evacuees (mainly from the Berlin and Hamburg metropolitan areas that were subject to air raids). After the war, people who fled and were expelled from the former eastern territories of Germany east of the Oder-Neisse line settled in Mecklenburg-Vorpommern (and elsewhere in Germany), increasing the population by 40%. Before the war, Mecklenburg and Western Pomerania had a population of 1,278,700, of whom many perished during the war and others moved west in the course of the Red Army's advance. In 1947, some 1,426,000 refugees from the former eastern parts of Germany were counted. Most of them settled in rural communities, but the urban population also increased, most notably in Schwerin from 65,000 (1939) to 99,518 (January 1947), in Wismar from 29,463 to 44,173, and in Greifswald from 29,488 to 43,897. Western Pomerania was additionally stripped of the area around the Pomeranian regional capital Stettin/Szczecin as well as the city itself, despite its location to the west of the river Oder.