State of the Teutonic Order in the context of "Battle of Grunwald"

Estonia, officially the Republic of Estonia, is a country in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the Baltic Sea across from Sweden, to the south by Latvia, and to the east by Russia. The territory of Estonia consists of the mainland, the larger islands of Saaremaa and Hiiumaa, and over 2,300 other islands and islets on the east coast of the Baltic Sea. Its capital Tallinn and Tartu are the two largest urban areas. The Estonian language, of the Finnic family, is the official language and the first language of the majority of its population of nearly 1.4 million. Estonia is one of the least populous members of the European Union and NATO.

Present-day Estonia has been inhabited since at least 9,000 BC. The medieval indigenous population of Estonia was one of the last pagan civilisations in Europe to adopt Christianity following the Northern Crusades in the 13th century. After centuries of successive rule by the Teutonic Order, Denmark, Sweden, and the Russian Empire, a distinct Estonian national identity began to emerge in the mid-19th century. This culminated in the 1918 Estonian Declaration of Independence from the then-warring Russian and German empires. Democratic throughout most of the interwar period, Estonia declared neutrality at the outbreak of World War II, but the country was repeatedly invaded and occupied, and ultimately annexed into the USSR. Throughout the de facto Soviet occupation, from World War II until 1991, Estonia's de jure state continuity was preserved by diplomatic representatives and the government-in-exile. Following the 1988–90 "Singing Revolution" against Soviet rule, full independence was restored on 20 August 1991.

Latvia, officially the Republic of Latvia, is a country in the Baltic region of northern Europe. It is one of the three Baltic states, along with Estonia to the north and Lithuania to the south. It borders Russia to the east and Belarus to the southeast and shares a maritime border with Sweden to the west. Latvia covers an area of 64,589 km (24,938 sq mi), with a population of 1.8 million. The country has a temperate seasonal climate. Its capital and largest city is Riga. Latvians, who are the titular nation and comprise 65.5% of the country's population, belong to the ethnolinguistic group of the Balts and speak Latvian. Russians are the most prominent minority in the country, at almost a quarter of the population; 37.7% of the population speak Russian as their native tongue.

After centuries of Teutonic, Swedish, Polish-Lithuanian, and Russian rule, the independent Republic of Latvia was established on 18 November 1918 after breaking away from the Russian Empire in the aftermath of World War I. The country became increasingly autocratic after the coup in 1934 established the dictatorship of Kārlis Ulmanis. Latvia's de facto independence was interrupted at the outset of World War II, beginning with forcible incorporation into the Soviet Union, followed by the invasion and occupation by Nazi Germany in 1941 and the re-occupation by the Soviets in 1944, which formed the Latvian SSR for the next 45 years. As a result of extensive immigration during the Soviet occupation, ethnic Russians became the most prominent minority in the country. The peaceful Singing Revolution started in 1987 among the Baltic Soviet republics and ended with the restoration of both de facto and official independence on 21 August 1991. Latvia has since been a democratic unitary parliamentary republic.

The concept of Germany as a distinct region in Central Europe can be traced to Julius Caesar, who referred to the unconquered area east of the Rhine as Germania, thus distinguishing it from Gaul. The victory of the Germanic tribes in the Battle of the Teutoburg Forest (AD 9) prevented annexation by the Roman Empire, although the Roman provinces of Germania Superior and Germania Inferior were established along the Rhine. Following the Fall of the Western Roman Empire, the Franks conquered the other West Germanic tribes. When the Frankish Empire was divided among Charles the Great's heirs in 843, the eastern part became East Francia, and later Kingdom of Germany. In 962, Otto I became the first Holy Roman Emperor of the Holy Roman Empire, the medieval German state.

During the High Middle Ages, the Hanseatic League, dominated by German port cities, established itself along the Baltic and North Seas. The development of a crusading element within German Christendom led to the Northern Crusades and the establishment of the State of the Teutonic Order along the Southern Baltic coast in what would later become Prussia. In the Investiture Controversy, the German Emperors resisted Catholic Church authority. In the Late Middle Ages, the regional dukes, princes, and bishops gained power at the expense of the emperors. Martin Luther led the Protestant Reformation within the Catholic Church after 1517, as the northern and eastern states became Protestant, while most of the southern and western states remained Catholic. The Thirty Years' War, a civil war from 1618 to 1648 brought tremendous destruction to the Holy Roman Empire. The estates of the empire attained great autonomy in the Peace of Westphalia, the most important being Austria, Prussia, Bavaria and Saxony. With the Napoleonic Wars, feudalism fell away and the Holy Roman Empire was dissolved in 1806. Napoleon established the Confederation of the Rhine as a German puppet state, but after the French defeat, the German Confederation was established under Austrian presidency. The German revolutions of 1848–1849 failed but the Industrial Revolution modernized the German economy, leading to rapid urban growth and the emergence of the socialist movement. Prussia, with its capital Berlin, grew in power. German universities became world-class centers for science and humanities, while music and art flourished. The unification of Germany was achieved under the leadership of the Chancellor Otto von Bismarck with the formation of the German Empire in 1871. The new Reichstag, an elected parliament, had only a limited role in the imperial government. Germany joined the other powers in colonial expansion in Africa and the Pacific.

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.

Germanisation, or Germanization, is the spread of the German language, people, and culture. It was a central idea of German conservative thought in the 19th and the 20th centuries, when conservatism and ethnic nationalism went hand in hand. In linguistics, Germanisation of non-German languages also occurs when they adopt many German words.

Under the policies of states such as the Teutonic Order, Austria, the Kingdom of Prussia, and the German Empire, non-German minorities were often discouraged or even prohibited from using their native language, and had their traditions and culture suppressed in the name of linguistic imperialism. In addition, the Government also encouraged immigration from the Germanosphere to further upset the linguistic balance, but with varying degrees of success. In Nazi Germany, linguistic Germanisation was replaced by a policy of genocide against Slavs even when they were already German-speaking.

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.

Royal Prussia (Polish: Prusy Królewskie; German: Königlich-Preußen or Preußen Königlichen Anteils, Kashubian: Królewsczé Prësë) or Polish Prussia (Polish: Prusy Polskie; German: Polnisch-Preußen) became a province of the Crown of the Kingdom of Poland, which was annexed following the Second Peace of Thorn (1466) from territory in Pomerelia and western Prussia which had been part of the State of the Teutonic Order. Royal Prussia retained its autonomy, governing itself and maintaining its own laws, customs, and rights.

In 1569, Royal Prussia was fully integrated into the Crown of the Kingdom of Poland and its autonomy was largely abolished. As a result, the Royal Prussian parliament was incorporated into the Sejm of the Polish–Lithuanian Commonwealth. In 1772 and 1793, after the first and second partition of Poland, the former territory of Royal Prussia was annexed by the Kingdom of Prussia and subsequently re-organized into the province of West Prussia. This occurred at the time of the First Partition of Poland, with other parts of the Polish–Lithuanian Commonwealth being annexed by the Russian Empire and Habsburg Austria.

Tallinn is the capital and most populous city of Estonia. Situated on a bay in north Estonia, on the shore of the Gulf of Finland of the Baltic Sea, it has a population of 456,518 as of 2025 and administratively lies in Harju County. Tallinn is the main governmental, financial, industrial, and cultural centre of Estonia. It is located 187 km (116 mi) northwest of the country's second largest city, Tartu, however, only 80 km (50 mi) south of Helsinki, Finland; it is also 320 km (200 mi) west of Saint Petersburg, Russia, 300 km (190 mi) north of Riga, Latvia, and 380 km (240 mi) east of Stockholm, Sweden. From the 13th century until the first half of the 20th century, Tallinn was known in most of the world by variants of its other historical name Reval.

Tallinn received Lübeck city rights in 1248; however, the earliest evidence of human settlement in the area dates back nearly 5,000 years. The medieval indigenous population of what is now Tallinn and north Estonia was one of the last "pagan" civilisations in Europe to adopt Christianity following the Papal-sanctioned Northern Crusades in the 13th century. The first recorded claim over the place was laid by Denmark after a successful raid in 1219 led by King Valdemar II, followed by a period of alternating Scandinavian and Teutonic rulers. Due to the strategic location by the sea, its port became a significant trade hub, especially in the 14–16th centuries, when Tallinn grew in importance as the northernmost member city of the Hanseatic League. Tallinn Old Town is one of the best-preserved medieval cities in Europe and is listed as a UNESCO World Heritage Site.