Free State of Prussia in the context of "Principality of Birkenfeld"

The Province of Pomerania (German: Provinz Pommern; Polish: Prowincja Pomorze) was a province of Prussia from 1815 to 1945. Pomerania was established as a province of the Kingdom of Prussia in 1815, an expansion of the older Brandenburg-Prussia province of Pomerania, and then became part of the German Empire in 1871. From 1918, Pomerania was a province of the Free State of Prussia until it was dissolved following World War II by decree of the Allied Control Council with the de jure abolition of Prussia on 25 February 1947, and its territory divided between Poland and Allied-occupied Germany. The city of Stettin (present-day Szczecin, Poland) was the provincial capital.

The Neumark (German pronunciation: [ˈnɔʏmaʁk] ), also known as the New March (Polish: Nowa Marchia) or as East Brandenburg (German: Ostbrandenburg [ˈɔstˌbʁandn̩bʊʁk] ), was a region of the Margraviate of Brandenburg and its successors located east of the Oder River in territory which became part of Poland in 1945 except some villages of former districts of Königsberg in the New March and Weststenberg remained in Germany.

Called the Lubusz Land while part of medieval Poland, the territory later known as the Neumark gradually became part of the German Margraviate of Brandenburg from the mid-13th century. As Brandenburg-Küstrin the Neumark formed an independent state of the Holy Roman Empire from 1535 to 1571; after the death of the margrave John, a younger son of Joachim I Nestor, Elector of Brandenburg, it returned to Elector John George, the margrave's nephew and Joachim I Nestor's grandson. With the rest of the Electorate of Brandenburg, it became part of the Kingdom of Prussia in 1701 and part of the German Empire in 1871 when each of those states first formed. After World War I the entirely ethnic German Neumark remained within the Free State of Prussia, itself part of the Weimar Republic (Germany).

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.

The Geheime Staatspolizei ([ɡəˈhaɪmə ˈʃtaːtspoliˌtsaɪ] , lit. 'Secret State Police'), abbreviated Gestapo ([ɡəˈstaːpo] ), was the official secret police of Nazi Germany and in German-occupied Europe.

The force was created by Hermann Göring in 1933 by combining the various political police agencies of Prussia into one organisation. On 20 April 1934, oversight of the Gestapo passed to the head of the Schutzstaffel (SS), Heinrich Himmler, who was also appointed Chief of German Police by Hitler in 1936. Instead of being exclusively a Prussian state agency, the Gestapo became a national one as a sub-office of the Sicherheitspolizei (SiPo; Security Police). From 27 September 1939, it was administered by the Reich Security Main Office (RSHA). It became known as Amt (Dept) 4 of the RSHA and was considered a sister organisation to the Sicherheitsdienst (SD; Security Service).

The Rhine Province (German: Rheinprovinz), also known as Rhenish Prussia (Rheinpreußen) or synonymous with the Rhineland (Rheinland), was the westernmost province of the Kingdom of Prussia and the Free State of Prussia, within the German Reich, from 1822 to 1946. It was created from the provinces of the Lower Rhine and Jülich-Cleves-Berg. Its capital was Koblenz, with the provincial assembly meeting in Düsseldorf. In 1939 it had 8 million inhabitants. The Province of Hohenzollern was militarily associated with the Oberpräsident of the Rhine Province. Also, for a short period of time, the Province of Hohenzollern was indirectly and de facto controlled by the Rhine Province.

The Rhine Province was bounded on the north by the Netherlands, on the east by the Prussian provinces of Westphalia and Hesse-Nassau, and the grand duchy of Hesse-Darmstadt, on the southeast by the Palatinate (a district of the Kingdom of Bavaria), on the south and southwest by Lorraine, and on the west by Luxembourg, Belgium and the Netherlands.

The Province of Nassau (German: Provinz Nassau) was a province of Prussia from 1944 to 1945.

Although all German states (including Prussia) had been de facto dissolved since 1933, the Nazi government formally partitioned the Prussian province of Hesse-Nassau into two provinces with a decree issued on 1 April 1944 and effective on 1 July 1944. The two new provinces were the province of Kurhessen and the province of Nassau.

Westphalia (/wɛstˈfeɪliə/; German: Westfalen [vɛstˈfaːlən]; Low German: Westfålen [vεs(t)ˈfɔːln]) is a region of northwestern Germany and one of the three historic parts of the state of North Rhine-Westphalia. It has an area of 20,210 square kilometres (7,800 sq mi) and 7.9 million inhabitants.

The territory of the region is almost identical with the historic Province of Westphalia, which was a part of the Kingdom of Prussia from 1815 to 1918 and the Free State of Prussia from 1918 to 1946. In 1946, Westphalia merged with North Rhine, another former part of Prussia, to form the newly created state of North Rhine-Westphalia. In 1947, the state with its two historic parts was joined by a third one: Lippe, a former principality and free state.

The Prussian State Council (German: Preußischer Staatsrat) was the second chamber of the bicameral legislature of the Free State of Prussia between 1921 and 1933; the first chamber was the Prussian Landtag (Preußischer Landtag). The members of the State Council were elected by the provincial parliaments and gave the provinces of Prussia a voice in the legislative process. The Council had an indirect right to introduce legislation, could object to bills passed by the Reichstag and had to approve expenditures that exceeded the budget.

Hanover (/ˈhænoʊvər, -nəv-/ HAN-oh-vər, HAN-ə-vər; German: Hannover [haˈnoːfɐ] ; Low German: Hannober) is the capital and largest city of the German state of Lower Saxony. Its population of 535,932 (2021) makes it the 13th-largest city in Germany as well as the fourth-largest in northern Germany after Berlin, Hamburg and Bremen. Hanover's urban area comprises the towns of Garbsen, Langenhagen and Laatzen and has a population of about 791,000 (2018). The Hanover Region has approximately 1.16 million inhabitants (2019) and is the largest in the Hanover–Braunschweig–Göttingen–Wolfsburg Metropolitan Region, the 17th biggest metropolitan area by GDP in the European Union.

Before it became the capital of Lower Saxony in 1946, Hanover was the capital of the Principality of Calenberg (1636–1692), the Electorate of Hanover (1692–1814), the Kingdom of Hanover (1814–1866), the Province of Hanover of the Kingdom of Prussia (1868–1918), the Province of Hanover of the Free State of Prussia (1918–1947) and of the State of Hanover (1946). From 1714 to 1837 Hanover was by personal union the family seat of the Hanoverian Kings of the United Kingdom of Great Britain and Ireland, under their title of the dukes of Brunswick-Lüneburg (later described as the Elector of Hanover).