East Prussia (located at the northeast corner of the map) was originally known as Prussia. It was established in the 13th century with the defeat by the Teutonic Knights over the Prussians. It became a duchy in 1525 and was united with the Mark of Brandenburg in 1618. In 1660, full independence from Polish authority was obtained by Friedrich Wilhelm, the Great Elector.
The original Borussi (Prussians) were Germanic people made up of many tribes, including Goths, Saxons, Vandals, Wends, and many others. One of these tribes was the Teutons, who was later defeated by the Romans. Possibly, they chose the word "Teutonic" as their race to distinguish themselves from other ethnic groups in Europe. During the 13th century, the Teutonic Knights welcomed a great influx of German citizens to the area because of their agricultural talents.
The 18th Century
The electors of Brandenburg gradually acquired other lands, and in 1701, Elector Friedrich III had himself crowned king in Prussia - as King Friedrich I. He originally was a prince of the Holy Roman Empire as elector of Brandenburg, but not king of Prussia, which lay outside imperial boundaries. This gave the kings of Prussia some independence from Emperor King Friedrich Wilhelm (who reigned 1713-1740) and worked to unify the state and build an efficient army.
In the Northern War of 1720, Prussia gained the eastern part of Swedish Pomerania. Through diplomacy, King Friedrich Wilhelm I unified and shaped the state. He also developed a government-controlled economy and conditioned its citizens in obedience and pride. Aristocrats were brought into the military and state service, then rewarded with land ownership, and were free to make serfs of the peasants.
Emperor King Friedrich II (reign: 1740-1786), known as Papa Fritz or Friedrich the Great, won most of Silesia from Austria in the War of the Austrian Succession and the Seven Year War (1756-1763). Prussia became the chief military power in Europe following this war. In 1772 Poland was partitioned and Pomerelia (except Danzig) was annexed; this became the province of West Prussia; the original Prussia became East Prussia. Friedrich Wilhelm II added additional territory from Poland between 1793 and 1795.
The 18th century social structure was similar and intertwined with the military system. The military cantonal system began in the 1730's by Friedrich Wilhelm 1. All the farmer's sons were obligated to register with the military and required to serve; if someone did not show up for military service, the family could lose their farm. However, they actually only served three months of each year and could return home the other nine months. There was a similar law regarding nobility. At the end of the 18th century this law was changed and soldiers served for a period of 20 years, while prior to this, their service was a life long obligation.
The 19th Century
Prussia lost all lands west of the Elbe and most of the lands acquired from Poland at the Treaty of Tilsit in 1807, as a result of the French Revolutionary War and Napoleon's War. In 1811, some constitution proposals for an improved economy by Wilhelm I failed to transpire and later those proposed by Friedrich Wilhelm IV were not practicable and failed also. An economic revolution in 1848 was brought down with force. Friedrich Wilhelm IV refused the imperial crown offered by the Frankfurt Parliament in 1849 because he wanted a German Union under Prussian leadership that would exclude Austria. He failed in his endeavor and Prussia remained the German Confederation.
Wilhelm I began his reign in 1858, became regent in 1861, became king in 1862, and appointed Otto von Bismarck as premier in 1862. Bismarck's first war in 1864, in an alliance with Austria, was fought against Denmark over Schleswig-Holstein. In the Austro-Prussian War in 1866, Austria and its allies were defeated almost immediately , and Prussia took over Hanover, Electoral Hesse, Nassau, Schleswig-Holstein, and Frankfurt am Main (previously a free city). The North German Confederation, led by Prussia, replaced the former German Confederation. The North German Confederation defeated France in the Franco-Prussian War (1870-1871). After territorial gains in the Austro-Prussian War and Franco-Prussian War, the Prussian king was proclaimed emperor of Germany and designated Wilhelm 1 of Germany. Bismark remained premier until 1890.
The 20th Century
Thereafter, Prussia's history was essentially that of Germany. Prussia, the former kingdom, was largest and most important of the German states and Berlin was the capital. It remained a kingdom in the German Empire until Germany became a republic in 1918. At that time the Junkers lost many of their estates because of the territorial loss to Poland. Subsequently in 1932, the Prussian parliament was dissolved and Social Democrat Otto Braun was expelled.
Adolph Hitler seized power over the German Empire in 1933 and appointed Hermann Göring premier of Prussia in 1934. The German states no longer existed as political units through a decree by Hitler in January of 1934. Prussia and Germany was united into one republic and it was no longer possible to tell where Germany and Prussia originally were located within the Unified Germany.
After World War II, as a result of the Allies (Russia, England, France and United States) at the Yalta Conference, Prussia was abolished as a state. In 1947, it was divided among West Germany, East Germany, the Russian Republic of the USSR (now Russia), and Poland. The residents of those areas were forced to flee to West Germany, or wherever they could find refuge.