Frederick William II of Prussia in the context of "Polish Constitution of May 3, 1791"

The Constitution of 3 May 1791, titled the Government Act, was a written constitution for the Polish–Lithuanian Commonwealth that was adopted by the Great Sejm that met between 1788 and 1792. The Commonwealth was a dual monarchy comprising the Crown of the Kingdom of Poland and the Grand Duchy of Lithuania; the new constitution was intended to address political questions following a period of political agitation and gradual reform that began with the Convocation Sejm of 1764 and the election that year of the Commonwealth's last monarch, Stanisław August Poniatowski. It was the first codified, modern constitution (possessing checks and balances and a tripartite separation of powers) in Europe and the second in the world, after that of the United States.

The Constitution sought to implement a more effective constitutional monarchy, introduced political equality between townspeople and nobility, and placed the peasants under the government's protection, mitigating the worst abuses of serfdom. It banned pernicious parliamentary institutions such as the liberum veto, which had put the Sejm at the mercy of any single deputy, who could veto and thus undo all the legislation adopted by that Sejm. The Commonwealth's neighbours reacted with hostility to the adoption of the Constitution. King Frederick William II of Prussia broke the Prussian alliance with the Commonwealth, joining with Imperial Russia under Catherine the Great and the anti-reform Targowica Confederation of Polish-Lithuanian magnates, to defeat the Commonwealth in the Polish–Russian War of 1792.

Wilhelm I (William I; William Frederick Louis; German: Wilhelm Friedrich Ludwig; 22 March 1797 – 9 March 1888) was King of Prussia from 1861 and German Emperor from 1871 until his death in 1888. A member of the House of Hohenzollern, he was the first head of state of a united Germany. He was regent of Prussia from 1858 to 1861 for his elder brother, King Frederick William IV. During the reign of his grandson Wilhelm II, he was known as Emperor Wilhelm the Great (German: Kaiser Wilhelm der Große).

The second son of Prince Frederick William and Louise of Mecklenburg-Strelitz, Wilhelm was not expected to ascend to the throne. His grandfather, King Frederick William II died the year he was born, and his father was crowned Frederick William III. Wilhelm fought with distinction during the War of the Sixth Coalition, and afterwards became a prominent figure within the Prussian Army. In 1840, his childless elder brother became King of Prussia, making him heir presumptive. Wilhelm played a major role in crushing the Revolutions of 1848 in Germany, although he was briefly forced into exile in England. Frederick William IV suffered a stroke in 1857 and was left incapacitated, and Wilhelm was formally named Prince Regent a year later. In 1861, Wilhelm ascended to the Prussian throne on his elder brother's death.

The Batavian Revolution (Dutch: De Bataafse Revolutie) was a time of political, social and cultural turmoil at the end of the 18th century that marked the end of the Dutch Republic and saw the proclamation of the Batavian Republic.

The initial period, from about 1780 to 1787, is known as the Patriottentijd or "Time of the Patriots". The power of the "Patriots" grew until the stadtholder, William V, felt he had to flee the country in 1785. He asked his brother-in-law Frederick William II of Prussia for help, and in 1787 a relatively small Prussian army restored the Orangists to power with little fighting.

The Brandenburg Gate (German: Brandenburger Tor [ˈbʁandn̩ˌbʊʁɡɐ ˈtoːɐ̯] ) is an 18th-century neoclassical monument in Berlin. One of the best-known landmarks of Germany, it was erected on the site of a former city gate that marked the start of the road from Berlin to Brandenburg an der Havel, the former capital of the Margraviate of Brandenburg. The current structure was built from 1788 to 1791 by orders of King Frederick William II of Prussia, based on designs by the royal architect Carl Gotthard Langhans. The bronze sculpture of the quadriga crowning the gate is a work by the sculptor Johann Gottfried Schadow.

The Brandenburg Gate is located in the western part of the city centre within Mitte, at the junction of Unter den Linden and Ebertstraße. The gate dominates the Pariser Platz to the east, while to the immediate west it opens onto the Platz des 18. März beyond which the Straße des 17. Juni begins. One block to the north stands the Reichstag building, home to the German parliament (Bundestag), and further to the west is the Tiergarten inner-city park. The gate also forms the monumental entry to Unter den Linden, which leads directly to the former City Palace of the Prussian monarchs (now housing the Humboldt Forum museum), and Berlin Cathedral.

The Declaration of Pillnitz was a statement of five sentences issued on 27 August 1791 at Pillnitz Castle near Dresden (Saxony) by Frederick William II of Prussia and the Habsburg Leopold II, Holy Roman Emperor who was Marie Antoinette's brother. It declared the joint support of the Holy Roman Empire and of Prussia for King Louis XVI of France against the French Revolution.

The New Garden (German: Neuer Garten) in Potsdam is a park of 102.5 hectares located southwest of Berlin, Germany, in northern Potsdam and bordering on the lakes Heiliger See and Jungfernsee. Starting in 1787, Frederick William II of Prussia (1744-1797) arranged to have a new garden laid out on this site, and the design and landscaping was carried out by Johann August Eyserbeck, who had previously worked on the Dessau-Wörlitz Garden Realm.

The New Garden, along with the Marmorpalais palace on its grounds and other palaces and parks in Potsdam and Berlin was inscribed on the UNESCO World Heritage List in 1990 because of its unique unity of architecture and landscaping and its testimony to the power of Prussia in the 17th and 18th centuries.