Duchy of Prussia in the context of "Masurians"

Königsberg is the historic German and Prussian name of the city now called Kaliningrad, Russia. The city was founded in 1255 on the site of the small Old Prussian settlement Twangste by the Teutonic Knights during the Baltic Crusades. It was named in honour of King Ottokar II of Bohemia, who led a campaign against the pagan Old Prussians, a Baltic tribe.

A Baltic port city, it successively became the capital of the State of the Teutonic Order, the Duchy of Prussia and the provinces of East Prussia and Prussia. Königsberg remained the coronation city of the Prussian monarchy from 1701 onwards, though the capital was Berlin. From the thirteenth to the twentieth centuries on, the inhabitants spoke predominantly German, although the city also had a profound influence upon the Lithuanian and Polish cultures. It was a publishing center of Lutheran literature; this included the first Polish translation of the New Testament, printed in the city in 1551, as well as the first book in Lithuanian and the first Lutheran catechism, both printed in Königsberg in 1547.

Prussia (/ˈprʌʃə/; German: Preußen [ˈpʁɔʏsn̩] ; Old Prussian: Prūsija) was a German state centred on the North European Plain that originated from the 1525 secularization act of the Prussian part of the State of the Teutonic Order. For centuries, the House of Hohenzollern ruled Prussia, expanding its size with the Prussian Army. Prussia, with its capital at Königsberg and then, when it became the Kingdom of Prussia in 1701, Berlin, decisively shaped the history of Germany. Prussia formed the German Empire when it united the German states in 1871. It was de facto dissolved by an emergency decree transferring powers of the Prussian government to German Chancellor Franz von Papen in 1932 and de jure by an Allied decree in 1947.

The name Prussia derives from the Old Prussians who were conquered by the Teutonic Knights – an organized Catholic medieval military order of German crusaders – in the 13th century. In 1308, the Teutonic Knights conquered the region of Pomerelia with Danzig. Their monastic state was mostly Germanised through immigration from central and western Germany, and, in the south, it was Polonised by settlers from Masovia. The imposed Second Peace of Thorn (1466) split Prussia into the western Royal Prussia, a province of Poland, and the eastern Duchy of Prussia, a feudal fief of the Crown of Poland until 1657. After 1525, the Teutonic Order relocated their headquarters to Mergentheim, but managed to keep land in Livonia until 1561. The union of Brandenburg and the Duchy of Prussia in 1618 led to the proclamation of the Kingdom of Prussia in 1701.

East Prussia (German: Ostpreußen [ˈɔstˌpʁɔɪ̯sn̩] ) was a province of the Kingdom of Prussia from 1772 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 the later province of East Prussia. During the 13th century, the native Prussians were conquered by the crusading Teutonic Knights. After the conquest they were gradually converted to Christianity. As a result of the medieval Ostsiedlung, Germans became the dominant ethnic group, while Poles and Lithuanians formed sizeable minorities. From the 13th century, the region of Prussia was part of the monastic state of the Teutonic Knights. After the Second Peace of Thorn in 1466 it became a part of the Kingdom of Poland, either directly (Warmia) or as a fief (remainder). In 1525, with the Prussian Homage, the territory became the Duchy of Prussia, a vassal duchy of Poland. It gained full sovereignty in 1657, when Poland renounced its feudal rights in the Treaty of Bromberg.

Klaipėda (/ˈkleɪpɛdə/ CLAY-ped-ə; Lithuanian: [ˈklˠɐɪ̯ˑpʲeːdˠɐ] ) is a city in Lithuania on the Baltic Sea coast. It is the third-largest city in Lithuania, the fifth-largest city in the Baltic States, the capital of Klaipėda County, the only major seaport in the country and the busiest port in the Baltic States.

The city has a complex recorded history, partially due to the combined regional importance of the usually ice-free port at the mouth of the river Akmena-Danė [lt]. It was situated in Lithuania Minor and successively belonged to the State of the Teutonic Order, the Duchy of Prussia (at times under the suzerainty of the Polish–Lithuanian Commonwealth), the Kingdom of Prussia and the German Empire, within which it was the northernmost big city until it was placed under French occupation in 1919. From 1923, the city was part of Lithuania until its annexation by Nazi Germany in 1939, and after World War II it was part of the Lithuanian Soviet Socialist Republic. Klaipėda has remained within Lithuania since 1944.

The House of Hohenzollern (/ˌhoʊənˈzɒlərn/, US also /-nˈzɔːl-, -ntˈsɔːl-/; German: Haus Hohenzollern, pronounced [ˌhaʊs hoːənˈtsɔlɐn] ; Romanian: Casa de Hohenzollern) is a formerly royal (and from 1871 to 1918, imperial) German dynasty whose members were variously princes, electors, kings and emperors of Hohenzollern, Brandenburg, Prussia, the German Empire, and Romania. The family came from the area around the town of Hechingen in Swabia during the late 11th century and took their name from Hohenzollern Castle. The first ancestors of the Hohenzollerns were mentioned in 1061.

The Hohenzollern family split into two branches, the Catholic Swabian branch and the Protestant Franconian branch, which ruled the Burgraviate of Nuremberg and later became the Brandenburg-Prussian branch. The Swabian branch ruled the principalities of Hohenzollern-Hechingen and Hohenzollern-Sigmaringen until 1849, and also ruled Romania from 1866 to 1947. Members of the Franconian branch became Margrave of Brandenburg in 1415 and Duke of Prussia in 1525.

The monarchs of Prussia were members of the House of Hohenzollern who were the hereditary rulers of the former German state of Prussia from its founding in 1525 as the Duchy of Prussia. The Duchy had evolved out of the Teutonic Order, a Roman Catholic crusader state and theocracy located along the eastern coast of the Baltic Sea. The Teutonic Knights were under the leadership of a Grand Master, the last of whom, Albert, converted to Protestantism and secularized the lands, which then became the Duchy of Prussia.

The Duchy was initially a vassal of the Kingdom of Poland, as a result of the terms of the Prussian Homage whereby Albert was granted the Duchy as part of the terms of peace following the Prussian War. When the main line of Prussian Hohenzollerns died out in 1618, the Duchy passed to a different branch of the family, who also reigned as Electors of Brandenburg in the Holy Roman Empire. While still nominally two different territories, Prussia under the suzerainty of Poland and Brandenburg under the suzerainty of the Holy Roman Empire, the two states are known together historiographically as Brandenburg-Prussia.

The rule of the Jagiellonian dynasty in Poland between 1386 and 1572 spans the Late Middle Ages and the Early Modern Period in European history. The Lithuanian Grand Duke Jogaila (Władysław II Jagiełło) founded the dynasty; his marriage to Queen Jadwiga of Poland in 1386 strengthened an ongoing Polish–Lithuanian union. The partnership brought vast territories controlled by the Grand Duchy of Lithuania into Poland's sphere of influence and proved beneficial for both the Polish and Lithuanian people, who coexisted and cooperated in one of the largest political entities in Europe for the next four centuries.

In the Baltic Sea region, Poland engaged in ongoing conflict with the Teutonic Knights. The struggles led to a major battle, the Battle of Grunwald of 1410, but there was also the milestone Peace of Thorn of 1466 under King Casimir IV Jagiellon; the treaty defined the basis of the future Duchy of Prussia. In the south, Poland confronted the Ottoman Empire and the Crimean Tatars, and in the east Poles helped Lithuania fight the Grand Duchy of Moscow. Poland's and Lithuania's territorial expansion included the far north region of Livonia.

The Margraviate of Brandenburg (German: Markgrafschaft Brandenburg) was a major principality of the Holy Roman Empire from 1157 to 1806 that, having electoral status although being quite poor, grew rapidly in importance after inheriting the Duchy of Prussia in 1618 and then came to play a pivotal role in the history of Germany and that of Central Europe as core of the Prussian kingdom.

Brandenburg developed out of the Northern March founded in the territory of the Slavic Wends. It derived one of its names from this inheritance, the March of Brandenburg (Mark Brandenburg). Its ruling margraves were established as prestigious prince-electors in the Golden Bull of 1356, allowing them to vote in the election of the Holy Roman Emperor. The state thus became additionally known as Electoral Brandenburg or the Electorate of Brandenburg (Kurbrandenburg or Kurfürstentum Brandenburg).

Brandenburg–Prussia (German: Brandenburg-Preußen; Low German: Brannenborg-Preußen) is the historiographic denomination for the early modern realm of the Brandenburgian Royal dynasty of the House of Hohenzollern between 1618 and 1701. Based in the Electorate of Brandenburg, the main branch of the Hohenzollern intermarried with the branch ruling the Duchy of Prussia, and secured succession upon the latter's extinction in the male line in 1618.

Another consequence of the intermarriage between the nobility was the acquisition / incorporation of the lands far to the west of Brandenburg–Prussia located in western Germany of the Holy Roman Empire (A.D. c. 800 / 962 to 1806), and situated in the lower Rhenish / Rhine River of the principalities of the Duchy of Cleves, County of Mark and County of Ravensberg after the signing and agreements in the Treaty of Xanten in 1614.

Frederick William (German: Friedrich Wilhelm; 16 February 1620 – 29 April 1688) was Elector of Brandenburg and Duke of Prussia, thus ruler of Brandenburg-Prussia, from 1640 until his death in 1688. A member of the House of Hohenzollern, he is popularly known as "the Great Elector" (der Große Kurfürst) because of his military and political achievements. Frederick William was a staunch pillar of the Calvinist faith, associated with the rising commercial class. He saw the importance of trade and promoted it vigorously. His shrewd domestic reforms gave Prussia a strong position in the post-Westphalian political order of Northern-Central Europe, setting up Prussia for elevation from duchy to kingdom, achieved under his son and successor.