Prussian CrusadeThe Prussian Crusade was a series of 13th-century campaigns of Roman Catholic crusaders, primarily led by the Teutonic Knights, to Christianize under duress the pagan Old Prussians. Invited after earlier unsuccessful expeditions against the Prussians by Christian Polish kings, the Teutonic Knights began campaigning against the Prussians, Lithuanians and Samogitians in 1230.
Prussia (region)Prussia (Old Prussian: Prūsa; Preußen; Prūsija; Prusy; Пруссия, Pruthenia/Prussia/Borussia) is a historical region in Europe on the south-eastern coast of the Baltic Sea, that ranges from the Vistula delta in the west to the end of the Curonian Spit in the east and extends inland as far as Masuria. This region is often also referred to as Old Prussia. Tacitus's Germania (98 AD) is the oldest known record of an eyewitness account on the territory and its inhabitants.
East PrussiaEast Prussia (Ostpreußen) was a province of the Kingdom of Prussia from 1773 to 1829 and again from 1878 (with the Kingdom itself being part of the German Empire from 1871); following World War I it formed part of the Weimar Republic's Free State of Prussia, until 1945. Its capital city was Königsberg (present-day Kaliningrad). East Prussia was the main part of the region of Prussia along the southeastern Baltic Coast. The bulk of the ancestral lands of the Baltic Old Prussians were enclosed within East Prussia.
Former eastern territories of GermanyThe "former eastern territories of Germany" (Ehemalige deutsche Ostgebiete) refer in present-day Germany to those territories east of the current eastern border of Germany i.e. the Oder–Neisse line which historically had been considered German and which were annexed by Poland and the Soviet Union after World War II in Europe. In many of these territories, Germans used to be the dominant or sole ethnicity.
Invasion of PolandThe Invasion of Poland, also known as the September Campaign, Polish Campaign, War of Poland of 1939, and Polish Defencive War of 1939 (1 September – 6 October 1939), was a joint attack on the Republic of Poland by Nazi Germany, the Slovak Republic, and the Soviet Union; which marked the beginning of World War II. The German invasion began on 1 September 1939, one week after the signing of the Molotov–Ribbentrop Pact between Germany and the Soviet Union, and one day after the Supreme Soviet of the Soviet Union had approved the pact.