Symbols

The main coat of arms of Prussia, as well as the flag of Prussia, depicted a black eagle on a white background.

The black and white national colours were already used by the Teutonic Knights and by the Hohenzollern dynasty. The Teutonic Order wore a white coat embroidered with a black cross with gold insert and black imperial eagle. The combination of the black and white colours with the white and red Hanseatic colours of the free cities Bremen, Hamburg and Lübeck, as well as of Brandenburg, resulted in the black-white-red commercial flag of the North German Confederation, which became the flag of the German Empire in 1871.

Suum cuique ("to each, his own"), the motto of the Order of the Black Eagle created by King Frederick I in 1701, was often associated with the whole of Prussia. The Iron Cross, a military decoration created by King Frederick William III in 1813, was also commonly associated with the country. The region, originally populated by Baltic Old Prussians who were Christianised, became a favoured location for immigration by (later mainly Protestant) Germans (see Ostsiedlung), as well as Poles and Lithuanians along the border regions.

Territory

Before its abolition, the territory of the Kingdom of Prussia included the provinces of West Prussia; East Prussia; Brandenburg; Saxony (including much of the present-day state of Saxony-Anhalt and parts of the state of Thuringia in Germany); Pomerania; Rhineland; Westphalia; Silesia (without Austrian Silesia); Schleswig-Holstein; Hanover; Hesse-Nassau; and a small detached area in the south called Hohenzollern, the ancestral home of the Prussian ruling family. The land that the Teutonic Knights occupied was flat and covered with fertile soil. The area was perfectly suited to the large-scale raising of wheat. The rise of early Prussia was based on the raising and selling of wheat. Teutonic Prussia became known as the "bread basket of Western Europe" (in German, Kornkammer, or granary). The port cities of Stettin (Szczecin) in Pomerania, Danzig (Gdańsk) in Prussia, Riga in Livonia, Königsberg (Kaliningrad), and Memel (Klaipėda) rose on the back of this wheat production. Wheat production and trade brought Prussia into a close relationship with the Hanseatic League during the period of time from 1356 (official founding of the Hanseatic League) until the decline of the League in about 1500.

The expansion of Prussia based on its connection with the Hanseatic League cut both Poland and Lithuania off from the coast of the Baltic Sea and trade abroad. This meant that Poland and Lithuania would be traditional enemies of Prussia, which was still called the Teutonic Knights.

History

Teutonic Order

In 1211 King Andrew II of Hungary granted Burzenland in Transylvania as a fiefdom to the Teutonic Knights, a German military order of crusading knights, headquartered in the Kingdom of Jerusalem at Acre. In 1225 he expelled them, and they transferred their operations to the Baltic Sea area. Konrad I, the Polish duke of Masovia, had unsuccessfully attempted to conquer pagan Prussia in crusades in 1219 and 1222. In 1226 Duke Konrad invited the Teutonic Knights to conquer the Baltic Prussian tribes on his borders.

During 60 years of struggles against the Old Prussians, the Order established an independent state that came to control Prūsa. After the Livonian Brothers of the Sword joined the Teutonic Order in 1237, the Order also controlled Livonia (now Latvia and Estonia). Around 1252 they finished the conquest of the northernmost Prussian tribe of the Skalvians as well as of the western Baltic Curonians, and erected Memel Castle, which developed into the major port city of Memel (Klaipėda). The Treaty of Melno defined the final border between Prussia and the adjoining Grand Duchy of Lithuania in 1422.

The Hanseatic League officially formed in northern Europe in 1356 as a group of trading cities. This League came to hold a monopoly on all trade leaving the interior of Europe and Scandinavia and on all sailing trade in the Baltic Sea for foreign countries. The merchants of the interiors of Sweden, Denmark, and Poland came to feel oppressed by the Hanseatic League.

In the course of the Ostsiedlung (German eastward expansion) process, settlers were invited, bringing changes in the ethnic composition as well as in language, culture, and law of the eastern borders of the German lands. As a majority of these settlers were Germans, Low German became the dominant language.

The Knights of the Teutonic Order were subordinate to the papacy and to the emperor. Their initially close relationship with the Polish Crown deteriorated after they conquered Polish-controlled Pomerelia and Danzig (Gdańsk) in 1308. Eventually, Poland and Lithuania, allied through the Union of Krewo (1385), defeated the Knights in the Battle of Grunwald (Tannenberg) in 1410.

The Thirteen Years' War (1454–1466) began when the Prussian Confederation, a coalition of Hanseatic cities of western Prussia, rebelled against the Order and requested help from the Polish king, Casimir IV Jagiellon. The Teutonic Knights were forced to acknowledge the sovereignty of, and to pay tribute to Casimir IV in the Second Peace of Thorn (1466), losing western Prussia (Royal Prussia) to Poland in the process. Pursuant to the Second Peace of Thorn, two Prussian states were established.

During the period of the monastic state of the Teutonic Knights, mercenaries from the Holy Roman Empire were granted lands by the Order and gradually formed a new landed Prussian nobility, from which the Junkers would evolve to take a major role in the militarization of Prussia and, later, Germany.

Duchy of Prussia

On 10 April 1525, after signing of the Treaty of Kraków, which officially ended the Polish–Teutonic War (1519–21), in the main square of the Polish capital Kraków, Albert I resigned his position as Grand Master of the Teutonic Knights and received the title "Duke of Prussia" from King Zygmunt I the Old of Poland. As a symbol of vassalage, Albert received a standard with the Prussian coat of arms from the Polish king. The black Prussian eagle on the flag was augmented with a letter "S" (for Sigismundus) and had a crown placed around its neck as a symbol of submission to Poland. Albert I, a member of a cadet branch of the House of Hohenzollern became a Lutheran Protestant and secularized the Order's Prussian territories. This was the area east of the mouth of the Vistula River, later sometimes called "Prussia proper". For the first time, these lands came into the hands of a branch of the Hohenzollern family, who already ruled the Margraviate of Brandenburg, since the 15th century. Furthermore, with his renunciation of the Order, Albert could now marry and produce legitimate heirs.

Brandenburg-Prussia

Brandenburg and Prussia united two generations later. In 1594 Anna, granddaughter of Albert I and daughter of Duke Albert Frederick (reigned 1568–1618), married her cousin Elector John Sigismund of Brandenburg. When Albert Frederick died in 1618 without male heirs, John Sigismund was granted the right of succession to the Duchy of Prussia, then still a Polish fief. From this time the Duchy of Prussia was in personal union with the Margraviate of Brandenburg. The resulting state, known as Brandenburg-Prussia, consisted of geographically disconnected territories in Prussia, Brandenburg, and the Rhineland lands of Cleves and Mark.

During the Thirty Years' War (1618–1648), various armies repeatedly marched across the disconnected Hohenzollern lands, especially the occupying Swedes. The ineffective and militarily weak Margrave George William (1619–1640) fled from Berlin to Königsberg, the historic capital of the Duchy of Prussia, in 1637. His successor, Frederick William I (1640–1688), reformed the army to defend the lands.

Frederick William I went to Warsaw in 1641 to render homage to King Władysław IV Vasa of Poland for the Duchy of Prussia, which was still held in fief from the Polish crown. In January 1656, during the first phase of the Second Northern War (1654–1660), he received the duchy as a fief from the Swedish king who later granted him full sovereignty in the Treaty of Labiau (November 1656). In 1657 the Polish king renewed this grant in the treaties of Wehlau and Bromberg. With Prussia, the Brandenburg Hohenzollern dynasty now held a territory free of any feudal obligations, which constituted the basis for their later elevation to kings.

Frederick William I became known as the "Great Elector" for his achievements in organizing the electorate, which he accomplished by establishing an absolute monarchy in Brandenburg-Prussia. Above all, he emphasised the importance of a powerful military to protect the state's disconnected territories, while the Edict of Potsdam (1685) opened Brandenburg-Prussia for the immigration of Protestant refugees (especially Huguenots), and he established a bureaucracy to carry out state administration efficiently.

Kingdom of Prussia

On 18 January 1701, Frederick William's son, Elector Frederick III, upgraded Prussia from a duchy to a kingdom and crowned himself King Frederick I. In the Crown Treaty of 16 November 1700, Leopold I, emperor of the Holy Roman Empire, allowed Frederick only to title himself "King in Prussia", not "King of Prussia". The state of Brandenburg-Prussia became commonly known as "Prussia", although most of its territory, in Brandenburg, Pomerania, and western Germany, lay outside Prussia proper. The Prussian state grew in splendour during the reign of Frederick I, who sponsored the arts at the expense of the treasury.

Frederick I was succeeded by his son, Frederick William I (1713–1740), the austere "Soldier King", who did not care for the arts but was thrifty and practical. He is considered the creator of the vaunted Prussian bureaucracy and the professionalised standing army, which he developed into one of the most powerful in Europe, although his troops only briefly saw action during the Great Northern War. In view of the size of the army in relation to the total population, Mirabeau said later: "Prussia, is not a state with an army, but an army with a state." Frederick William also settled more than 20,000 Protestant refugees from Salzburg in thinly populated eastern Prussia, which was eventually extended to the west bank of the River Memel, and other regions. In the treaty of Stockholm (1720), he acquired half of Swedish Pomerania.

The king died in 1740 and was succeeded by his son, Frederick II, whose accomplishments led to his reputation as "Frederick the Great". As crown prince, Frederick had focused, primarily, on philosophy and the arts. He was an accomplished flute player. In 1740, Prussian troops crossed over the undefended border of Silesia and occupied Schweidnitz. Silesia was the richest province of Habsburg Austria. It signalled the beginning of three Silesian Wars (1740–1763). The First Silesian War (1740–1742) and the Second Silesian War (1744–1745) have, historically, been grouped together with the general European war called the War of Austrian Succession (1740–1748). Holy Roman Emperor Charles VI had died on 20 October 1740. He was succeeded to the throne by his daughter, Maria Theresa.

By defeating the Austrian Army at the Battle of Mollwitz on 10 April 1741, Frederick succeeded in conquering Lower Silesia (the northwestern half of Silesia). In the next year, 1742, he conquered Upper Silesia (the southeastern half). Furthermore, in the third Silesian War (usually grouped with the Seven Years' War) Frederick won a victory over Austria at the Battle of Lobositz on 1 October 1756. In spite of some impressive victories afterward, his situation became far less comfortable the following years, as he failed in his attempts to knock Austria out of the war and was gradually reduced to a desperate defensive war. However, he never gave up and on 3 November 1760 the Prussian king won another battle, the hard-fought Battle of Torgau. Despite being several times on the verge of defeat Frederick, allied with Great Britain, Hanover and Hesse-Kassel, was finally able to hold the whole of Silesia against a coalition of Saxony, the Habsburg Monarchy, France and Russia. Voltaire, a close friend of the king, once described Frederick the Great's Prussia by saying "...it was Sparta in the morning, Athens in the afternoon."

Silesia, full of rich soils and prosperous manufacturing towns, became a vital region to Prussia, greatly increasing the nation's area, population, and wealth. Success on the battleground against Austria and other powers proved Prussia's status as one of the great powers of Europe. The Silesian Wars began more than a century of rivalry and conflict between Prussia and Austria as the two most powerful states operating within the Holy Roman Empire (although both had extensive territory outside the empire). In 1744, the County of East Frisia fell to Prussia following the extinction of its ruling Cirksena dynasty.

In the last 23 years of his reign until 1786, Frederick II, who understood himself as the "first servant of the state", promoted the development of Prussian areas such as the Oderbruch. At the same time he built up Prussia's military power and participated in the First Partition of Poland with Austria and Russia in 1772, an act that geographically connected the Brandenburg territories with those of Prussia proper. During this period, he also opened Prussia's borders to immigrants fleeing from religious persecution in other parts of Europe, such as the Huguenots. Prussia became a safe haven in much the same way that the United States welcomed immigrants seeking freedom in the 19th century.

Frederick the Great, from 1772 the first "King of Prussia", practised enlightened absolutism. He introduced a general civil code, abolished torture and established the principle that the Crown would not interfere in matters of justice. He also promoted an advanced secondary education, the forerunner of today's German gymnasium (grammar school) system, which prepares the brightest pupils for university studies. The Prussian education system was emulated in various countries, including the United States.

Napoleonic Wars

During the reign of King Frederick William II (1786–1797), Prussia annexed additional Polish territory through the Second Partition of Poland in 1793 and the Third Partition of Poland in 1795. His successor, Frederick William III (1797–1840), announced the union of the Prussian Lutheran and Reformed churches into one church.

Prussia took a leading part in the French Revolutionary Wars, but remained quiet for more than a decade due to the Peace of Basel of 1795, only to go once more to war with France in 1806 as negotiations with that country over the allocation of the spheres of influence in Germany failed. Prussia suffered a devastating defeat against Napoleon Bonaparte's troops in the Battle of Jena-Auerstedt, leading Frederick William III and his family to flee temporarily to Memel. Under the Treaties of Tilsit in 1807, the state lost about one-third of its area, including the areas gained from the second and third Partitions of Poland, which now fell to the Duchy of Warsaw. Beyond that, the king was obliged to pay a large indemnity, to cap his army at 42,000 men, and to let the French garrison troops throughout Prussia, effectively making the Kingdom a French satellite.

In response to this defeat, reformers such as Stein and Hardenberg set about modernising the Prussian state. Among their reforms were the liberation of peasants from serfdom, the Emancipation of Jews and making full citizens of them. The school system was rearranged, and in 1818 free trade was introduced. The process of army reform ended in 1813 with the introduction of compulsory military service for men. By 1813, Prussia could mobilize almost 300,000 soldiers, more than half of which were conscripts of the Landwehr of variable quality. The rest consisted of regular soldiers that were deemed excellent by most observers, and very determined to repair the humiliation of 1806.

After the defeat of Napoleon in Russia, Prussia quit its alliance with France and took part in the Sixth Coalition during the "Wars of Liberation" (Befreiungskriege) against the French occupation. Prussian troops under Marshal Gebhard Leberecht von Blücher contributed crucially (alongside the British and Dutch) to the final victory over Napoleon in the Battle of Waterloo of June 1815. Prussia's reward in 1815 at the Congress of Vienna was the recovery of her lost territories, as well as the whole of the Rhineland, Westphalia, 40% of Saxony and some other territories. These western lands were of vital importance because they included the Ruhr Area, the centre of Germany's fledgling industrialisation, especially in the arms industry. These territorial gains also meant the doubling of Prussia's population. In exchange, Prussia withdrew from areas of central Poland to allow the creation of Congress Poland under Russian sovereignty. In 1815 Prussia became part of the German Confederation.

Wars of liberation

The first half of the 19th century saw a prolonged struggle in Germany between liberals, who wanted a united, federal Germany under a democratic constitution, and conservatives, who wanted to maintain Germany as a patchwork of independent, monarchical states with Prussia and Austria competing for influence. One small movement that signaled a desire for German unification in this period was the Burschenschaft student movement, by students who encouraged the use of the black-red-gold flag, discussions of a unified German nation, and a progressive, liberal political system. Because of Prussia's size and economic importance, smaller states began to join its free trade area in the 1820s. Prussia benefited greatly from the creation in 1834 of the German Customs Union (Zollverein), which included most German states but excluded Austria.

In 1848 the liberals saw an opportunity when revolutions broke out across Europe. Alarmed, King Frederick William IV agreed to convene a National Assembly and grant a constitution. When the Frankfurt Parliament offered Frederick William the crown of a united Germany, he refused on the grounds that he would not accept a crown from a revolutionary assembly without the sanction of Germany's other monarchs.

The Frankfurt Parliament was forced to dissolve in 1849, and Frederick William issued Prussia's first constitution by his own authority in 1850. This conservative document provided for a two-house parliament. The lower house, or Landtag was elected by all taxpayers, who were divided into three classes whose votes were weighted according to the amount of taxes paid. Women and those who paid no taxes had no vote. This allowed just over one-third of the voters to choose 85% of the legislature, all but assuring dominance by the more well-to-do men of the population. The upper house, which was later renamed the Herrenhaus ("House of Lords"), was appointed by the king. He retained full executive authority and ministers were responsible only to him. As a result, the grip of the landowning classes, the Junkers, remained unbroken, especially in the eastern provinces.

Wars of unification

In 1862 King Wilhelm I appointed Otto von Bismarck as Prime Minister of Prussia. Bismarck was determined to defeat both the liberals and conservatives and increase Prussian supremacy and influence among the German states. There has been much debate as to whether Bismarck actually planned to create a united Germany when he set out on this journey, or whether he simply took advantage of the circumstances that fell into place. Certainly his memoirs paint a rosy picture of an idealist , but these were written with the benefit of hindsight and certain crucial events could not have been predicted. What is clear is that Bismarck curried support from large sections of the people by promising to lead the fight for greater German unification. He eventually guided Prussia through three wars, which together brought William the position of German Emperor.

Schleswig Wars

The Kingdom of Denmark was at the time in personal union with the Duchies of Schleswig and Holstein, both of which had close ties with each other, although only Holstein was part of the German Confederation. When the Danish government tried to integrate Schleswig, but not Holstein, into the Danish state, Prussia led the German Confederation against Denmark in the First War of Schleswig (1848–1851). Because Russia supported Austria, Prussia also conceded predominance in the German Confederation to Austria in the Punctation of Olmütz in 1850.

In 1863, Denmark introduced a shared constitution for Denmark and Schleswig. This led to conflict with the German Confederation, which authorised the occupation of Holstein by the Confederation, from which Danish forces withdrew. In 1864, Prussian and Austrian forces crossed the border between Holstein and Schleswig initiating the Second War of Schleswig. The Austro-Prussian forces defeated the Danes, who surrendered both territories. In the resulting Gastein Convention of 1865 Prussia took over the administration of Schleswig while Austria assumed that of Holstein.

Austro-Prussian War

Bismarck realised that the dual administration of Schleswig and Holstein was only a temporary solution, and tensions rose between Prussia and Austria. The struggle for supremacy in Germany then led to the Austro-Prussian War (1866), triggered by the dispute over Schleswig and Holstein, with Bismarck using proposed injustices as the reason for war.

On the Austrian side stood the south German states (including Bavaria and Württemberg), some central German states (including Saxony), and Hanover in the north. On the side of Prussia were Italy, most north German states, and some smaller central German states. Eventually, the better-armed Prussian troops won the crucial victory at the Battle of Königgrätz under Helmuth von Moltke the Elder. The century-long struggle between Berlin and Vienna for the dominance of Germany was now over. As a sideshow in this war, Prussia defeated Hanover in the Battle of Langensalza (1866). While Hanover hoped in vain for help from Britain (as they had previously been in personal union), Britain stayed out of a confrontation with a continental great power and Prussia satisfied its desire for merging the once separate territories and gaining strong economic and strategic power, particularly from the full access to the resources of the Ruhr.

Bismarck desired Austria as an ally in the future, and so he declined to annex any Austrian territory. But in the Peace of Prague in 1866, Prussia annexed four of Austria's allies in northern and central Germany—Hanover, Hesse-Kassel (or Hesse-Cassel), Nassau and Frankfurt. Prussia also won full control of Schleswig-Holstein. As a result of these territorial gains, Prussia now stretched uninterrupted across the northern two-thirds of Germany and contained two-thirds of Germany's population. The German Confederation was dissolved, and Prussia impelled the 21 states north of the Main River into forming the North German Confederation.

Prussia was the dominant state in the new confederation, as the kingdom comprised almost four-fifths of the new state's territory and population. Prussia's near-total control over the confederation was secured in the constitution drafted for it by Bismarck in 1867. Executive power was held by a president, assisted by a chancellor responsible only to him. The presidency was a hereditary office of the Hohenzollern rulers of Prussia. There was also a two-house parliament. The lower house, or Reichstag (Diet), was elected by universal male suffrage. The upper house, or Bundesrat (Federal Council) was appointed by the state governments. The Bundesrat was, in practice, the stronger chamber. Prussia had 17 of 43 votes, and could easily control proceedings through alliances with the other states.

As a result of the peace negotiations, the states south of the Main remained theoretically independent, but received the (compulsory) protection of Prussia. Additionally, mutual defence treaties were concluded. However, the existence of these treaties was kept secret until Bismarck made them public in 1867 when France tried to acquire Luxembourg.

Franco-Prussian War

The controversy with the Second French Empire over the candidacy of a Hohenzollern to the Spanish throne was escalated both by France and Bismarck. With his Ems Dispatch, Bismarck took advantage of an incident in which the French ambassador had approached William. The government of Napoleon III, expecting another civil war among the German states, declared war against Prussia, continuing Franco-German enmity. However, honouring their treaties, the German states joined forces and quickly defeated France in the Franco-Prussian War in 1870. Following victory under Bismarck's and Prussia's leadership, Baden, Württemberg and Bavaria, which had remained outside the North German Confederation, accepted incorporation into a united German Empire.

The empire was a "Lesser German" solution (in German, "kleindeutsche Lösung") to the question of uniting all German-speaking peoples into one state, because it excluded Austria, which remained connected to Hungary and whose territories included non-German populations. On 18 January 1871 (the 170th anniversary of the coronation of King Frederick I), William was proclaimed "German Emperor" (not "Emperor of Germany") in the Hall of Mirrors at Versailles outside Paris, while the French capital was still under siege.

German Empire

The two decades after the unification of Germany were the peak of Prussia's fortunes, but the seeds for potential strife were built into the Prusso-German political system.

The constitution of the German Empire was a slightly amended version of the North German Confederation's constitution. Officially, the German Empire was a federal state. In practice, Prussia's relationship with the rest of the empire was somewhat confusing. The Hohenzollern kingdom included three-fifths of the German territory and two-thirds of its population. The Imperial German Army was, in practice, an enlarged Prussian army, although the other kingdoms (Bavaria, Saxony and Württemberg) retained their own armies. The imperial crown was a hereditary office of the House of Hohenzollern, the royal house of Prussia. The prime minister of Prussia was, except for two brief periods (January–November 1873 and 1892–94), also imperial chancellor. But the empire itself had no right to collect taxes directly from its subjects; the only incomes fully under federal control were the customs duties, common excise duties, and the revenue from postal and telegraph services. While all men above age 25 were eligible to vote in imperial elections, Prussia retained its restrictive three-class voting system. This effectively required the king/emperor and prime minister/chancellor to seek majorities from legislatures elected by two different franchises. In both the kingdom and the empire, the original constituencies were never redrawn to reflect changes in population, meaning that rural areas were grossly overrepresented by the turn of the 20th century.

As a result, Prussia and the German Empire were something of a paradox. Bismarck knew that his new German Reich was now a colossus out of all proportion to the rest of the continent. With this in mind, he declared Germany a satisfied power, using his talents to preserve peace, for example at the Congress of Berlin. Bismarck had barely any success in some of his domestic policies, such as the anti-Catholic Kulturkampf, but he also had mixed success on ones like Germanisation or expulsion of Poles of foreign nationality (Russian or Austro-Hungarian).

Frederick III became emperor in March 1888, after the death of his father, but he died of cancer only 99 days later. At age 29, Wilhelm became Kaiser Wilhelm II after a difficult youth and conflicts with his British mother Victoria, Princess Royal. He turned out to be a man of limited experience, narrow and reactionary views, poor judgment, and occasional bad temper, which alienated former friends and allies.

Railways

Prussia nationalised its railways in the 1880s in an effort both to lower rates on freight service and to equalise those rates among shippers. Instead of lowering rates as far as possible, the government ran the railways as a profitmaking endeavour, and the railway profits became a major source of revenue for the state. The nationalisation of the railways slowed the economic development of Prussia because the state favoured the relatively backward agricultural areas in its railway building. Moreover, the railway surpluses substituted for the development of an adequate tax system.

The Free State of Prussia in the Weimar Republic

Because of the German Revolution of 1918, Wilhelm II abdicated as German Emperor and King of Prussia. Prussia was proclaimed a "Free State" (i.e. a republic, German: Freistaat) within the new Weimar Republic and in 1920 received a democratic constitution.

Almost all of Germany's territorial losses, specified in the Treaty of Versailles, were areas that had been part of Prussia: Eupen and Malmedy to Belgium; North Schleswig to Denmark; the Memel Territory to Lithuania; the Hultschin area to Czechoslovakia. Many of the areas Prussia annexed in the partitions of Poland, such as the Provinces of Posen and West Prussia, as well as eastern Upper Silesia, went to the Second Polish Republic. Danzig became the Free City of Danzig under the administration of the League of Nations. Also, the Saargebiet was created mainly from formerly Prussian territories. East Prussia became an exclave, only reachable by ship (the Sea Service East Prussia) or by a railway through the Polish corridor.

The German government seriously considered breaking up Prussia into smaller states, but eventually traditionalist sentiment prevailed and Prussia became by far the largest state of the Weimar Republic, comprising 60% of its territory. With the abolition of the older Prussian franchise, it became a stronghold of the left. Its incorporation of "Red Berlin" and the industrialised Ruhr Area, both with working-class majorities, ensured left-wing dominance.

From 1919 to 1932, Prussia was governed by a coalition of the Social Democrats, Catholic Centre and German Democrats; from 1921 to 1925, coalition governments included the German People's Party. Unlike in other states of the German Reich, majority rule by democratic parties in Prussia was never endangered. Nevertheless, in East Prussia and some rural areas, the Nazi Party of Adolf Hitler gained more and more influence and popular support, especially from the lower middle class starting in 1930. Except for Catholic Upper Silesia, the Nazi Party in 1932 became the largest party in most parts of the Free State of Prussia. However, the democratic parties in coalition remained a majority, while Communists and Nazis were in the opposition.

The East Prussian Otto Braun, who was Prussian minister-president almost continuously from 1920 to 1932, is considered one of the most capable Social Democrats in history. He implemented several trend-setting reforms together with his minister of the interior, Carl Severing, which were also models for the later Federal Republic of Germany (FRG). For instance, a Prussian minister-president could be forced out of office only if there was a "positive majority" for a potential successor. This concept, known as the constructive vote of no confidence, was carried over into the Basic Law of the FRG. Most historians regard the Prussian government during this time as far more successful than that of Germany as a whole.

In contrast to its pre-war authoritarianism, Prussia was a pillar of democracy in the Weimar Republic. This system was destroyed by the Preußenschlag ("Prussian coup") of Reich Chancellor Franz von Papen. In this coup d'état, the government of the Reich deposed the Prussian government on 20 July 1932, under the pretext that the latter had lost control of public order in Prussia (during the Bloody Sunday of Altona, Hamburg, which was still part of Prussia at that time) and by using fabricated evidence that the Social Democrats and the Communists were planning a joint putsch. The Defence Minister General Kurt von Schleicher, who was the prime mover behind the coup manufactured evidence that the Prussian police under Braun's orders were favouring the Communist Rotfrontkämpferbund in street clashes with the SA as part of an alleged plan to foment a Marxist revolution, which he used to get an emergency decree from President Paul von Hindenburg imposing Reich control on Prussia. Papen appointed himself Reich commissioner for Prussia and took control of the government. The Preußenschlag made it easier, only half a year later, for Hitler to take power decisively in Germany, since he had the whole apparatus of the Prussian government, including the police, at his disposal.

Prussia and the Third Reich

After the appointment of Hitler as the new chancellor, the Nazis used the absence of Franz von Papen as an opportunity to appoint Hermann Göring federal commissioner for the Prussian ministry of the interior. The Reichstag election of 5 March 1933 strengthened the position of the National Socialist German Workers' Party (NSDAP or "Nazi" Party), although they did not achieve an absolute majority.

The Reichstag building having been set on fire a few weeks earlier on 27 February, a new Reichstag was opened in the Garrison Church of Potsdam on 21 March 1933 in the presence of President Paul von Hindenburg. In a propaganda-filled meeting between Hitler and the Nazi Party, the "marriage of old Prussia with young Germany" was celebrated, to win over the Prussian monarchists, conservatives and nationalists and induce them into supporting and subsequently voting in favor of the Enabling Act of 1933.

In the centralised state created by the Nazis in the "Law on the Reconstruction of the Reich" ("Gesetz über den Neuaufbau des Reichs", 30 January 1934) and the "Law on Reich Governors" ("Reichsstatthaltergesetz", 30 January 1935) the states were dissolved, in fact if not in law. The federal state governments were now controlled by governors for the Reich who were appointed by the chancellor. Parallel to that, the organisation of the party into districts (Gaue) gained increasing importance, as the official in charge of a Gau (the head of which was called a Gauleiter) was again appointed by the chancellor who was at the same time chief of the Nazi Party.

This centralistic policy went even further in Prussia. From 1934 to 1945, almost all ministries were merged and only a few departments were able to maintain their independence. Hitler himself became formally the governor of Prussia. However, his functions were exercised by Hermann Göring as Prussian prime minister.

As provided for in the "Greater Hamburg Act" ("Groß-Hamburg-Gesetz"), certain exchanges of territory took place. Prussia was extended on 1 April 1937, for instance, by the incorporation of the Free and Hanseatic City of Lübeck.

The Prussian lands transferred to Poland after the Treaty of Versailles were re-annexed during World War II. However, most of this territory was not reintegrated back into Prussia but assigned to separate Gaue of Danzig-West Prussia and Wartheland during much of the duration of the war.

The end of Prussia

The areas east of the Oder-Neisse line, mainly Eastern Prussia, Western Prussia, and Silesia, were ceded over to Poland and the Soviet Union in 1945 due to the Treaty of Potsdam between three of the Allies: the United States, United Kingdom, and the Soviet Union. This included important Prussian cities like Danzig, Königsberg, Breslau, and Stettin. The population fled, mostly to the Western zones, or was driven out. The number of casualties is estimated 2 to 4 million, including those who fled the Soviet army during the last months of the war before the treaty.

As part of their wartime goals, the Western allies sought the abolition of Prussia. Stalin was initially content to retain the name, Russians having a different historical view of their neighbour and sometime former ally. Nonetheless by Law No. 46, which was accepted and implemented by the Allied Control Council on 25 February 1947, Prussia was officially proclaimed to be dissolved.

In the Soviet occupation zone, which became East Germany (officially, the German Democratic Republic) in 1949, the former Prussian territories were reorganised into the states of Brandenburg and Saxony-Anhalt, with the remaining parts of the Province of Pomerania going to Mecklenburg-Vorpommern. These states were de facto abolished in 1952 in favour of Bezirke (districts), but were recreated after German reunification in 1990.

In the Western Zones of occupation, which became West Germany (officially, the Federal Republic of Germany) in 1949, the former Prussian territories were divided up among North Rhine-Westphalia, Lower Saxony, Hesse, Rhineland-Palatinate and Schleswig-Holstein. Württemberg-Baden and Württemberg-Hohenzollern were later merged with Baden to create the state of Baden-Württemberg. The Saar region, which had been administered by the French as a protectorate separate from the rest of Western Germany, was admitted to the Federal Republic of Germany as a separate state in 1956 following a plebiscite.

One year later, in 1957, the Prussian Cultural Heritage Foundation was established and implemented by federal statutes in West Germany in response to a ruling from the Federal Constitutional Court of Germany. The fundamental goal of this institution is protecting the cultural legacy of Prussia. It continues to operate from its headquarters in Berlin to this very day.

Administrative and constitutional frameworks

In the mid-16th century the margraves of Brandenburg had become highly dependent on the Estates (representing counts, lords, knights, and towns, but not prelates, due to the Protestant Reformation in 1538). The margraviate's liabilities and tax income as well as the margrave's finances were in the hands of the Kreditwerk, an institution not controlled by the elector, and of the Großer Ausschuß ("Great Committee") of the Estates. This was due to concessions made by Elector Joachim II in 1541 in return for financial aid by the estates; however, the Kreditwerk went bankrupt between 1618 and 1625. The margraves further had to yield to the veto of the Estates in all issues concerning the "better or worse of the country", in all legal commitments, and in all issues concerning pawn or sale of the elector's real property.

To reduce the influence of the Estates, in 1604, Joachim Frederick created a council called Geheimer Rat für die Kurmark ("Privy Council for the Electorate", which instead of the Estates would function as the supreme advisory council for the elector. While the council was permanently established in 1613, it failed to gain any influence until 1651, due to the Thirty Years' War (1618–1648)

Until after the Thirty Years' War, the various territories of Brandenburg-Prussia remained politically independent from each other, connected only by the common feudal superior. Frederick William (ruled 1640–1688), who envisioned the transformation of the personal union into a real union, started to centralise the Brandenburg-Prussian government with an attempt to establish the Geheimer Rat as a central authority for all territories in 1651, but this project proved infeasible. Instead, the elector continued to appoint a governor (Kurfürstlicher Rat) for each territory, who in most cases was a member of the Geheimer Rat. The most powerful institution in the territories remained the governments of the estates (Landständische Regierung, named Oberratsstube in Prussia and Geheime Landesregierung in Mark and Cleves), which were the highest government agencies regarding jurisdiction, finances and administration. The elector attempted to balance the Estates' governments by creating Amtskammer chambers to administer and coordinate the elector's domains, tax income and privileges. Such chambers were introduced in Brandenburg in 1652, in Cleves and Mark in 1653, in Pomerania in 1654, in Prussia in 1661 and in Magdeburg in 1680. Also in 1680, the Kreditwerk came under the aegis of the elector.

Frederick William I's excise tax (Akzise), which from 1667 replaced the property tax raised in Brandenburg for Brandenburg-Prussia's standing army with the Estates' consent, was raised by the elector without consultation with the Estates. The conclusion of the Second Northern War of 1655–1660 had strengthened the elector politically, enabling him to reform the constitution of Cleves and Mark in 1660 and 1661 to introduce officials loyal to him and independent of the local estates. In the Duchy of Prussia he confirmed the traditional privileges of the Estates in 1663, but the latter accepted the caveat that these privileges were not to be used to interfere with the exertion of the elector's sovereignty. As in Brandenburg, Frederick William ignored the privilege of the Prussian Estates to confirm or veto taxes raised by the elector: while in 1656, an Akzise was raised with the Estates' consent, the elector by force collected taxes not approved by the Prussian Estates for the first time in 1674. From 1704 the Prussian estates de facto relinquished their right to approve the elector's taxes while formally still entitled to do so. In 1682 the elector introduced an Akzise to Pomerania and in 1688 to Magdeburg, while in Cleves and Mark an Akzise was introduced only between 1716 and 1720. Due to Frederick William I's reforms, the state income increased threefold during his reign, and the tax burden per subject reached a level twice as high as in France.

Under the rule of Frederick III (I) (in office: 1688–1713), the Brandenburg Prussian territories were de facto reduced to provinces of the monarchy. Frederick William's testament would have divided Brandenburg-Prussia among his sons, but his firstborn son Frederick III (I), with the emperor's backing, succeeded in becoming the sole ruler based on the Treaty of Gera of 1599, which forbade a division of Hohenzollern territories. In 1689, a new central chamber for all Brandenburg-Prussian territories was established, called Geheime Hofkammer (from 1713: Generalfinanzdirektorium). This chamber functioned as a superior agency of the territories' Amtskammer chambers. The General War Commissariat (Generalkriegskommissariat) emerged as a second central agency, superior to the local Kriegskommissariat agencies initially concerned with the administration of the army, but before 1712 transformed into an agency also concerned with general tax and police tasks.

The Kingdom of Prussia functioned as an absolute monarchy until the Revolutions of 1848 in the German states, after which Prussia became a constitutional monarchy and Adolf Heinrich von Arnim-Boitzenburg was elected as Prussia's first prime minister (Ministerpräsident). Prussia's first constitution dated from 1848. The 1850 Prussian Constitution established a two-chamber parliament. The lower house, or Landtag represented all taxpayers, who were divided into three classes according to the amount of taxes paid. This allowed just over 25% of the voters to choose 85% of the legislature, all but assuring dominance by the more well-to-do elements of the population. The upper house (First Chamber or Erste Kammer), later renamed the Prussian House of Lords (Herrenhaus), was appointed by the king. He retained full executive authority and ministers were responsible only to him. As a result, the grip of the landowning classes, the Junkers, remained unbroken, especially in the eastern provinces. The Prussian Secret Police, formed in response to the Revolutions of 1848 in the German states, aided the conservative government.

Unlike its authoritarian pre-1918 predecessor, Prussia from 1918 to 1932 was a promising democracy within Germany. The abolition of the political power of the aristocracy transformed Prussia into a region strongly dominated by the left wing of the political spectrum, with "Red Berlin" and the industrial centre of the Ruhr Area exerting major influence. During this period a coalition of centre-left parties ruled, predominantly under the leadership (1920–1932) of East Prussian Social Democrat Otto Braun. While in office Braun implemented several reforms (together with his Minister of the Interior, Carl Severing) that became models for the later Federal Republic of Germany. For instance, a Prussian prime minister could only be forced out of office if there was a "positive majority" for a potential successor. This concept, known as the constructive vote of no confidence, became part of the Basic Law of the Federal Republic of Germany. Most historians regard the Prussian government during the 1920s as far more successful than that of Germany as a whole.

Similar to other German states both now and at the time, executive power remained vested in a Minister-President of Prussia and in laws established by a Landtag elected by the people.

Demographics

Population

In 1871, Prussia's population numbered 24.69 million, accounting for 60% of the German Empire's population. In 1910, the population had increased to 40.17 million (62% of the Empire's population). In 1914, Prussia had an area of 354,490 km2. In May 1939 Prussia had an area of 297,007 km2 and a population of 41,915,040 inhabitants. The Principality of Neuenburg, now the Canton of Neuchâtel in Switzerland, was a part of the Prussian kingdom from 1707 to 1848.

Religion

The Duchy of Prussia was the first state to officially adopt Lutheranism in 1525. In the wake of the Reformation, Prussia was dominated by two major Protestant confessions: Lutheranism and Calvinism. The majority of the Prussian population was Lutheran, although there were dispersed Reformed minorities in central and western parts of the state especially Brandenburg, Rhineland, Westphalia and Hesse-Nassau. In 1613, John Sigismund, Elector of Brandenburg and Grand Duke of Prussia declared himself for the Reformed creed and transferred the Berlin Cathedral from the Lutheran to the Reformed church. Lutherans and Reformed congregations all over the kingdom were merged in 1817 by the Prussian Union of churches, which came under tight royal control. In Protestant regions, writes Nipperdey:

Prussia received significant Huguenot population after the issuing of the Edict of Fontainebleau by Louis XIV of France and the following dragonnades. Prussian monarchs, beginning with Frederick William, Elector of Brandenburg opened the country to the fleeing French Calvinist refugees. In Berlin, they built and worshipped at their own church called the French Cathedral on Gendarmenmarkt. Time passed by, and the French Reformed assimilated into the wider Protestant community in Prussia. East Prussia's southern region of Masuria was mostly made up of Germanised Lutheran Masurians.

After 1814, Prussia contained millions of Roman Catholics in the west and in the east. There were substantial populations in the Rhineland, parts of Westphalia, eastern parts of Silesia, West Prussia, Ermland and the Province of Posen. Communities in Poland were often ethnically Polish, although this is not the case of eastern Silesia as the majority of Catholics there were German. During the 19th-century Kulturkampf, Prussian Catholics were forbidden from fulfilling any official functions for the state and were largely distrusted.

Prussia contained a relatively large Jewish community, which was mostly concentrated in large urban areas. According to the 1880 census, it was the biggest one in Germany with 363,790 individuals.

In 1925, 64.9% of the Prussian population was Protestant, 31.3% was Roman Catholic, 1.1% was Jewish, 2.7% was placed in other religious categories.

Non-German population

In 1871, approximately 2.4 million Poles lived in Prussia, constituting the largest minority. Other minorities were Jews, Danes, Frisians, Dutchmen, Kashubians (72,500 in 1905), Masurians (248,000 in 1905), Lithuanians (101,500 in 1905), Walloons, Czechs, Kursenieki, and Sorbs.

The area of Greater Poland, where the Polish nation had originated, became the Province of Posen after the Partitions of Poland. Poles in this Polish-majority province (62% Polish, 38% German) resisted German rule. Also, the southeast portion of Silesia (Upper Silesia) had a Polish majority. But Catholics and Jews did not have equal status with Protestants.

As a result of the Treaty of Versailles in 1919, the Second Polish Republic was granted not only these two areas, but also areas with a German majority in the Province of West Prussia. After World War II, East Prussia, Silesia, most of Pomerania and the eastern part of Brandenburg were either annexed by the Soviet Union or given to Poland, and the German-speaking populations forcibly expelled.

File:CretiusEmpfang.jpg|King Frederick William I of Prussia welcoming the expelled Salzburg Protestants

File:Dom, Berlin 1900.png|The Berlin Cathedral

File:Prussian deportations.PNG|Prussian deportations (Polenausweisungen) were the mass expulsions of ethnic Poles between 1885 and 1890.

条顿骑士团的始末

地理和民族

由法理上来说，普鲁士这块地方并不属于德意志，因为其本来不属于神圣罗马帝国的疆界范围，只是因为后来勃兰登堡选侯与普鲁士公国合并，是为普鲁士王国，于是成为德意志帝国的一部分。在中世纪早期，普鲁士这块地方是蛮荒之地，古代的居民为古普鲁士人，所使用的普鲁士语属于波罗的语族，与拉脱维亚人和立陶宛人属于同一种族。928年，布兰登堡就已经由萨克森公爵狮子亨利建城，此后在不同的家族之间继承和易手。

普鲁士的德意志化

12世纪时，德意志人的殖民运动开始进入波罗的海东岸地区。1170年，波美拉尼亚的索比斯劳公爵在普鲁士地区建立第一个殖民地，即但泽附近的奥利瓦修道院，1224年该修道院被古普鲁士人焚毁。1226年，波兰王国国王之子、马佐维亚公国首领康拉德公爵（条顿骑士团成员）的领地也遭到古普鲁士人袭击，以此为契机，条顿骑士团在普鲁士地区发动为时近200年的东征运动，先后建立托伦、马林堡、库尔姆、埃尔平等要塞，普鲁士成了条顿骑士团的地盘，德意志人、波兰人、立陶宛人和欧洲其他种族纷纷前来移民。条顿骑士团迫使其皈依基督教，使用德语。16世纪后，古普鲁士人同化于德意志人，所使用的普鲁士语也逐渐消失。

条顿骑士团的一蹶不振

条顿骑士团统治下的普鲁士地区在名义上属于教宗领地，但教宗只享有名义上的宗主权。为了吸引定居者，条顿骑士团依据汉萨同盟法律，在其领土上兴建一系列自由市。1379年条顿骑士团加入汉萨同盟。1370年波兰王室男嗣断绝；1386年波兰国王的女儿海德维希嫁给立陶宛大公、波兰与立陶宛联合；此后为保护其出海口和夺回历史上的领地、与条顿骑士团发生一连串战争。在1410年7月15日的格伦瓦德之战（或第一次坦能堡会战）中、条顿骑士团败于波兰和立陶宛联军，被迫签订第一次托伦和约；除赔款600万葛罗琛外，还将但泽置于波兰主权之下。1466年条顿骑士团再度战败，在第二次托伦和约中被迫割让包括但泽和马林堡在内的西普鲁士。这些地区被称为「王室普鲁士」，实际上已成为波兰的一个行省。条顿骑士团保留普鲁士的残馀领土，而且要效忠波兰国王，成为波兰的附庸。

勃兰登堡兴起

与普鲁士联系之开端

1512年，来自勃兰登堡霍亨索伦家族的阿尔布雷希特被选为条顿骑士团总团长，他是勃兰登堡选帝侯的近亲。在马丁·路德的影响下，1525年他宣布改信路德宗，从而切断与骑士团名义宗主罗马教廷的联系，随后宣布解散骑士团，改为普鲁士公国，阿尔布雷希特自任普鲁士公爵，成为臣服于波兰最高权力之下的世俗君主。

1618年，阿尔布雷希特之子阿尔布雷希特·腓特烈死后无子，普鲁士公国遂由其长女之夫、勃兰登堡选帝侯国的约翰·西吉斯蒙德（属霍亨索伦家族）继承，建立勃兰登堡-普鲁士公国。此举为霍亨索伦王朝日后发展奠定基础。

反抗宗主国-波兰

1640年继位的勃兰登堡选帝侯腓特烈·威廉在中击败瑞典，从此号称「大选帝侯」。三十年战争之后，布兰登堡开始经营一支小型的军队。1655年第二次北方战争（瑞典-波兰战争）爆发，布兰登堡一开始作为瑞典的盟友参战，1660年波兰战败，勃兰登堡大选帝侯腓特烈·威廉取消波兰对普鲁士的宗主权，从此布兰登堡拥有东普鲁士的完全主权，不用再向波兰国王称臣，腓特烈·威廉并建立起中央集权的政治制度。1672年，法荷战争和第三次英荷战争爆发。瑞典是英法的盟友，而勃兰登堡军队则是神圣罗马帝国军队中的一支。1688年「大选帝侯」腓特烈·威廉病死，传位与子选帝侯腓特烈三世。

腓特烈一世时代

18世纪初，勃兰登堡大选帝侯之子腓特烈三世（腓特烈·威廉之子）支持奥地利哈布斯堡王朝向法国波旁王朝宣战，藉以换取国王级别的称号。1701年1月18日，腓特烈三世在柯尼斯堡创建新的国王称号并加冕成为「在普鲁士的国王」腓特烈一世，并非直接称之为『普鲁士国王』。自此，普鲁士作为一个王国才正式存在，并从此展开普鲁士王国两百多年的侵略扩张史。

腓特烈二世时代

由于继承条顿骑士团的军事专制传统，普鲁士的军队向来以纪律严明、教育质素高而闻名于世，尤其是腓特烈二世以绝顶的好运著称。他在1740年继承王位、即位7个月之后即向垄断神圣罗马帝国的皇位的奥地利哈布斯堡进攻，目的在于夺取人口相当于整个普鲁士王国、而且工农业极其发达、离普鲁士最接近的西里西亚。从而引发奥地利王位继承战争（这场战争引起腓特烈二世和玛丽娅特蕾茜雅的世仇和日后依附于奥地利的外交策略）、第二次西里西亚战争和七年战争；后来甚至为了连接东普鲁士和西普鲁士、不惜背上被人唾弃的駡名而和自己的敌人奥地利帝国和俄罗斯帝国联手瓜分自己的宗主国波兰立陶宛联邦，史称第一次瓜分波兰。

通过一系列的侵略战争，腓特烈二世树立军事天才的个人威望、并将普鲁士变为一个国家军队的一部份（非军队是国家机器的一部份）。但此时，腓特烈二世已步入晚年。奥地利虽然失去西里西亚，但因为有瓜分波兰做的补偿、所以元气早已恢复；波兰立陶宛联邦虽遭到第一次瓜分，但核心领土未损、而且瓜分后新创立的军政改革制度使她的军队比以前强大。为了攻占西里西亚、腓特烈二世已经消耗完今生大部份精力；虽然建立军事天才的个人威望、但整个普鲁士国家在欧洲的国际地位依然只是个次强，所以不得不在被普鲁士侵略过领土的波兰立陶宛和奥地利、这个两个欧洲列强中争取一方的和平和妥协；最后普鲁士的历代君主都选择与奥地利共同进退的外交政策、直到俾斯麦的出现为止。

腓特烈二世同时还从伏尔泰那里接受启蒙运动思想，改进司法和教育制度、鼓励宗教信仰自由、并扶植科学和艺术的发展。到1786年腓特烈二世去世时，普鲁士已经成为欧洲准列强之一（其行政机构的高效率和廉洁为欧洲之首）；但是国际地位仍然离法国和奥地利帝国这种传统欧陆强国有很长一段距离。

腓特烈·威廉二世

半波兰的普鲁士

腓特烈·威廉二世继承王位后、因为保持著向奥地利靠拢的外交策略，所以不再对奥地利的波西米亚有任何领土幻想；于是他推行强权政治，把侵略目标东进、联合俄罗斯进行第二次瓜分波兰，最后还主动向奥地利示好、邀请她参与第三次瓜分波兰。瓜分波兰后的普鲁士王国中，波兰人的人口就占了一半，是名符其实的双民族（半波兰半普鲁士）国家，也成为正式的列强；假使这个领土范围一直保持到19世纪末和20世纪初，普鲁士可能就会像奥匈帝国一样不得不向从属民族（在奥地利为匈牙利民族、在普鲁士为波兰民族）进行妥协、变为二元君主制。

但普鲁士的命运并不是如此。她先后购买安斯巴赫侯国和拜罗伊特侯国；这两个领土看似渺小且无关紧要，但这却是的日后的普鲁士在德国西部的落脚点和扩张的起点；普鲁士为了把东部的普鲁士本土和西部的工商业发达地区连接起来绞尽脑汁、从侧面推动普鲁士自发主动的统一德国（而不是像奥地利那样，虽然是德意志第一强国、但处处被动）。

法国大革命后，普鲁士因为受到奥地利和英国的邀请、参加反法同盟，结果大败于法军，普鲁士战无不胜的神话消失一半；因此在1795年同意法国兼并莱茵河以西的德意志领土，而把莱茵河以东的德意志邦国纳入自己的势力范围。表面上看来，半波兰半普鲁士的命运是不可逆转的了；但是历史却偏向无法预料的方向。

腓特烈·威廉三世

腓特烈·威廉三世（1797年即位）于1806年10月参加反法战争，随即在耶拿被拿破仑的击溃，被迫逃往柯尼斯堡，这使得普鲁士军的神话彻底粉碎。1807年普鲁士和法国在涅曼河的提尔西特缔结和约，普鲁士割让16万平方公里土地，包括普属波兰的绝大部分领土（第二次、第三次瓜分波兰所得，以及第一次瓜分波兰所得领土的南半部），以及易北河以西的全部领土，并赔款1.3亿法郎。这一连串看似屈辱的条约，到日后反倒成为普鲁士统一德国的基石；丢失大部份波兰领土，不但让普鲁士没有像奥地利一样深陷多民族国家的深渊无法自拔、而且给她德国统一后的单一的、纯粹的德意志民族。

1806年惨败后，普鲁士首相卡尔·施泰因开始推行改革，其措施包括：让公民参与政治以唤醒其民族主义情感、释放农奴、实行地方自治、改组中央政府机构。1809年在柏林创办腓特烈·威廉大学（柏林大学），同时格哈德·冯·沙恩霍斯特开始对普鲁士军队进行改革。此后普鲁士的爱国主义情绪高涨。1812年冬，拿破仑军队自俄国败退；普鲁士遂于次年再度参加反法同盟，于1813年3月17日对法国宣战。10月24日，俄奥普三国联军在布吕歇尔和格奈森瑙指挥下在莱比锡大败法军；1815年英军联合三国联军在滑铁卢再度击败法军。

根据奥地利的梅特涅主导的维也纳会议；普鲁士仅仅在旧波兰恢复5%（其馀划给俄罗斯），但因为自己本身在德国西部有领土、所以得到默麦尔河到莱茵河的领土作为补偿（居民大多是天主教徒）；成为德意志邦联内德语区居民最多的国家。奥地利的梅特涅虽然把普鲁士的领土一切两半、中间还有英王的直属国汉诺威，加上自己奥地利本身就很庞大、还获得大量北意大利和克罗地亚的领土；但其中德语区的奥地利部份只占奥地利帝国总面积的15%，日后庞大的奥地利帝国必定被错综复杂的民族关系给拖累。

俄罗斯获得大部份波兰、但也同时增加更多波兰人独立的隐患，原本一分为三的波兰如今大部份在俄罗斯境内、重新整合的波兰人自然会奋起独立。与此同时，民族单一的普鲁士就没有那么多问题；加上拿破仑战争后、被国际社会正式承认为欧洲列强之一（虽然是敬陪末座），在德意志的领导权已经和奥地利相差无几（去除奥地利的传统权威、实际上普鲁士的影响力已经超过奥地利，只不过在当时人们还无法预见而已）。

不过这些影响力的发挥，都要等到1820年代中期，才渐渐现出端倪。当时欧洲首强——日不落帝国（大英帝国）改采光荣孤立的路线，逐渐切断它和共主盟邦汉诺威的联系（后来更因为1837年维多利亚女王的登基而完全分离），于是在1828年普鲁士开始和其他的德意志邦国筹组关税同盟，终于在1834年有德意志关税同盟的出现；当初奥相梅特涅设想让汉诺威切断普鲁士东西联系的计画，随著1851年汉诺威加入德意志关税同盟而宣告瓦解。

统一德国之路

俾斯麦时代

1834年，普鲁士在德意志地区建立德意志关税同盟，除奥地利和汉堡外，全部德意志邦国都加入该同盟。

1848年，欧洲革命期间，普王腓特烈·威廉四世宣布成立「自由派政府」。召开制宪会议，并拒绝接受德意志国民议会奉上的「德意志皇帝」称号与宪法，打算趁奥地利忙于扑灭革命的空档，强迫多数诸邦国奉其为联盟共主。

1850年，腓特烈·威廉四世在俄、奥的武力恫吓下，放弃称霸的计画，乖顺地回到德意志邦联之内。

1853年，克里米亚战争爆发，维持将近五十年的俄奥联盟瓦解，双方反目成仇；加上1852年由拿破仑三世成立的法兰西第二帝国，特别敌视奥地利并处心积虑要给予打击，于是在普鲁士眼前，突然出现一个可以自由挥洒的国际空间。

1857年，腓特烈·威廉四世患上精神病，以其弟威廉担任摄政王。

1861年，腓特烈·威廉四世逝世，摄政王即位，称威廉一世。

1862年，他因军事改革所需预算及税收问题与国会发生冲突，本拟退位，但在前驻法大使俾斯麦的建议下收回成命。俾斯麦表示支持军事改革，并称若任命他担任首相，他将不惜一切强行推行陆军改革和新兵役制度。9月22日，威廉一世任命俾斯麦担任首相。

俾斯麦上台后，即著手策划德意志统一大业。俾斯麦主张建立将奥地利排除在外的「小德意志」。普鲁士在1864年和1866年先后在普丹战争中击败丹麦和在普奥战争中击败奥地利，并在1870年领导北德意志邦联及南方的德意志诸邦，在普法战争中击败法国。威廉一世于1871年1月18日（即普鲁士王国成立170周年纪念日）在法国凡尔赛宫镜厅登基，成为德意志帝国的皇帝，宣布建立以普鲁士王国为首的德意志帝国。

由于普鲁士拥有德意志帝国近七成的人口和六成的领土，并且在军事、经济、工业等方面远远超过帝国内其他欧洲王国、公国，因此德意志帝国成为普鲁士王国的扩大版。各邦国享有内政和财政的自治，但将外交、军事（巴伐利亚除外）、海关等权力交给德意志帝国中央政府。普鲁士历史从此并入德意志帝国历史。

威廉二世的德意志帝国时代

1888年，威廉一世之子腓特烈三世在位99天后去世。其孙威廉二世登基，成为德意志帝国的第三代皇帝。所谓「功高盖主」，威廉二世登基后第一件事就是罢黜俾斯麦这个统一德国、但权力却淩驾于皇帝之上的宰相。虽然威廉二世在开疆扩土和外交上不及俾斯麦的老谋深算，但在内政和殖民上却远超他的前宰相。德意志帝国境内的旧容克贵族、新兴的资产阶级、平民、工人、新教徒、天主教徒、犹太人、波兰人第一次被完整的联合在一起。因为他的海外殖民政策和对俄国态度的急转直下几乎团结之前反抗帝国统治的所有异议者；不但如此，而且威廉二世善于运用『大日耳曼主义』、『大海军主义』、『阳光下的地盘』等足够能鼓动人心的口号来向所有德意志人民和国内非日耳曼人开了一张令人向往的空头支票。所有人都相信自己国家的未来一片美好，但却忽视了严酷的外交，最终这个曾经用了3年就统一全德意志的帝国、只走了47年就悄然从历史的舞台上退场。

德意志帝国的致命伤是她贫乏且不计后果的外交策略，德国位于欧洲的中央、又因为普法战争中给法国人带来难以磨灭的羞辱，导致她的外交政策必定将『围堵法国』作为最优先的考量；而且，德国已经与一个强大的邻国发生矛盾、不想再另加新的敌人，所以都不得不在各种外交场合支持与自己领土接壤最多的奥匈帝国，以此换取奥国不和法国结盟的可能；俄罗斯帝国原本是普鲁士忠实的盟友，但是接连遭到德·奥两国在外交上的背叛，以至于破天荒和英国与世仇法国重新交好。德意志帝国一建立，就注定她的外交失败、也注定她的命运必定和奥匈紧紧地绑在一起；仅因为奥匈这个「活跃的配角」而深陷外交孤立和资源短缺无法自拔、还和她的盟友一起掉入国内各种起义和革命的深渊、最后被名为一战的车轮碾得粉碎。

1918年11月7日，巴伐利亚发生革命，其国王退位。柏林旋即爆发革命，要求德皇退位。其时威廉二世在比利时斯巴的德军大本营亲自指挥作战，得知发生革命后，试图仅放弃德意志皇帝头衔，而保留普鲁士国王称号，但陆军统帅兴登堡劝其彻底退位。为避免发生更大变乱，德国总理马克斯·冯·巴登亲王于11月9日午前宣布德皇已经退位，并于同日将首相职务移交德国社会民主党领袖弗里德里希·艾伯特。

威廉二世流亡荷兰，德意志帝国及普鲁士王国灭亡。11月11日，德国向协约国投降。

1919年至1947年的普鲁士

由于柏林发生斯巴达克团与社会民主党临时政府之间的内战，1919年，艾伯特在魏玛召开国民议会，于2月10日通过《德意志共和国临时约法》，即魏玛宪法。根据魏玛宪法，普鲁士成为德国的一个邦，即「普鲁士自由邦」，实行地方自治，其领土即原普鲁士王国的疆域。但凡尔赛条约将原普鲁士王国的西普鲁士省、波森省和上西里西亚省的一部分割让给波兰，东普鲁士的默麦尔割让给立陶宛，莱茵兰的南部地区成立萨尔区，石勒苏益格北部归还丹麦。

1920年代，普鲁士自由邦政府多由德国社会民主党和天主教中央党领导。1932年，纳粹党在德国国会和普鲁士邦选举中取得优势，赫尔曼·戈林成为德国国会议长以及普鲁士邦议长，并掌握普鲁士内政部和警察。1933年1月30日纳粹党上台执政，随后废除德国的地方自治制度，普鲁士宪法被废除，邦议会和立法机构被解散，仅保留行政单位。

第二次世界大战中，同盟国和苏联的领导人经过多次会议，达成共识，即普鲁士是德国军国主义的发源地、德国军官团和容克贵族的大本营，是德国专制思想及侵略思想的策源地，必须予以消灭。美国总统罗斯福在德黑兰会议上曾表示「普鲁士要让其尽可能地缩小和削弱」，丘吉尔则认为「普鲁士——这个德国军国主义的罪恶核心必须同德国的其馀部分分离开来」。雅尔塔会议和波茨坦会议确立将奥得河—尼斯河以东并入波兰和苏联，以及在战后的德国废除普鲁士建制的原则性意见。

1947年2月25日，同盟国对德军事管制最高委员会颁布法案第46号，普鲁士被正式宣布取消建制。原普鲁士邦领土分别被并入波兰和苏联，以及英、法、美、苏四国占领区。原普鲁士邦政府的财产由盟国和苏联共同瓜分。

1949年德意志民主共和国成立后，在其境内的原普鲁士领土上建立勃兰登堡、萨克森-安哈特两个州，以及梅克伦堡-西波美拉尼亚州的东半部（1952年民主德国废除州级建制，改设专区）。在德意志联邦共和国，在原普鲁士领土上成立的州包括北莱茵-威斯特法伦州和石勒苏益格-荷尔斯泰因州。此外，下萨克森州、莱茵兰-普法尔茨州、黑森州、巴登-符滕堡州和萨尔州内都有原普鲁士王国和普鲁士邦领土。在被并入波兰和苏联的普鲁士领土上，德意志族居民已经被全部驱逐。

领土变迁

古代普鲁士地区仅包括今日立陶宛以南、波兰东北部维斯瓦河河口以西、以但泽为中心的西普鲁士地区，以及俄罗斯加里宁格勒原东普鲁士地区的领土。1295年占据普鲁士的条顿骑士团购买波美拉尼亚和但泽地区。1308年自勃兰登堡选帝侯手中购买纽马克地区，普鲁士同神圣罗马帝国本土接壤。15世纪时将但泽和西普鲁士割让给波兰。

1618年普鲁士公国并入勃兰登堡选侯国，至1701年普鲁士王国成立的时候，其领土以普鲁士王国的首都柏林为中心，包括勃兰登堡、波美拉尼亚、纽马克和阿尔特马克，以及德意志南部的霍亨索伦-西格马林根地区。18世纪时，普鲁士先后从瑞典、波兰和奥地利获得前波美拉尼亚、波森、西里西亚等地区。三次瓜分波兰后，普鲁士获得新东普鲁士、南普鲁士、但泽、托伦、以及波兰王国的西部和中部，包括华沙地区。1806年普鲁士败于拿破仑后，被迫割让波兰地区，法国在此成立华沙公国。拿破仑战败后，在1815年维也纳会议上，普鲁士失去拜罗伊特、安斯巴赫、纳沙泰尔（后加入瑞士）、东弗里斯兰、希尔德斯海姆等领地，华沙大公国除西部以波森为中心的一小块领土外都被俄国吞并。作为补偿，普鲁士获得萨克森王国五分之二的领土，以及德意志西部的汉诺威、明斯特主教区、莱茵河东西两岸的威斯特伐利亚和莱茵兰、以及萨尔路易、萨尔布吕肯等领土。

19世纪，普鲁士经过战争，又先后兼并黑森-莱茵、石勒苏益格、荷尔斯泰因、法兰克福等王国、公国和自由市。到1871年成立德意志帝国时，普鲁士王国已经拥有22个省，包含巴伐利亚、巴登、符腾堡以外的大部分现今德国领土与西波兰及北波兰。

第一次世界大战后，原属普鲁士王国的波森省、西普鲁士和但泽割让给波兰，默麦尔地区割让给立陶宛，石勒苏益格的北部归还丹麦，莱茵兰地区南端被并入萨尔区。第二次世界大战后，根据盟军定下的奥德河-尼斯河线，界线以东的东普鲁士、西里西亚及波美拉尼亚被并入苏联及波兰；普鲁士的西部地区并入西德，中部并入东德，地理意义上成建制的普鲁士已不复存在。而在1947年2月25日，占领德国的盟军管制委员会颁布第46号暂行法,宣布「普鲁士国中央政府及附属各级机关即日起解散」。同日,联合国管理委员会又颁布了第47条法令,宣布「以普鲁士为名的国家正式灭亡,并不获承认」。

教育文化

普鲁士王国除了建军武备，完成德国统一大业外，在文化教育上的贡献也被后人所称道。贯彻民族主义教育。米拉波曾经说过：「其他国家都是拥有军队的国家，但普鲁士是个拥有国家的军队。」

1717年，普鲁士王国开始实施义务国民教育，是全世界第一个实施义务教育的国家，也为往后普鲁士高素质的军队奠定扎实的基础。

1809年威廉·冯·洪堡出任普鲁士最高教育长官后，开始改革普鲁士的教育制度，更成为德国后来二百年的科学、技术、文化发展的基石。

1810年，成立的柏林大学，则是第一所新制大学，更影响世界各国十九世纪的高等教育发展。