North German Confederation in the context of "Franco-Prussian War"

The German Empire (German: Deutsches Reich), also referred to as Imperial Germany, the Second Reich, or simply Germany, was the period of the German Reich from the unification of Germany in 1871 until the November Revolution in 1918, when Germany changed its form of government to a republic. The German Empire consisted of 25 states, each with its own nobility: four constituent kingdoms, six grand duchies, five duchies (six before 1876), seven principalities, three free Hanseatic cities, and one imperial territory. While Prussia was only one of the four kingdoms in the realm, it contained about two-thirds of the Empire's population and territory, and Prussian dominance was also constitutionally established, since the King of Prussia was also the German Emperor (Deutscher Kaiser).

The empire was founded on 18 January 1871, when the south German states, except for Austria, Switzerland and Liechtenstein, joined the North German Confederation. The new constitution came into force on 16 April, changing the name of the federal state to the German Empire and introducing the title of German Emperor for Wilhelm I, King of Prussia from the House of Hohenzollern. Berlin remained its capital, and Otto von Bismarck, Minister President of Prussia, became chancellor, the head of government. After 1850, the states of Germany had rapidly become industrialized. In 1871, Germany had a population of 41 million people; by 1913, this had increased to 68 million. A heavily rural collection of states in 1815, the now united Germany became predominantly urban. German factories were often larger and more modern than many of their British and French counterparts, but the preindustrial sector was more backward. The success of the German Empire in the natural sciences was such that one-third of all Nobel Prizes went to German inventors and researchers. During its 47 years of existence, the German Empire became an industrial, technological, and scientific power in Europe, and by 1913, Germany was the largest economy in continental Europe and the third largest in the world. Germany also became a great power, building the longest railway network of Europe, the world's strongest army, and a fast-growing industrial base. Starting very small in 1871, in a decade, the navy became second only to Britain's Royal Navy.

Otto Eduard Leopold, Prince of Bismarck, Count of Bismarck-Schönhausen, Duke of Lauenburg (/ˈbɪzmɑːrk/; born Otto Eduard Leopold von Bismarck-Schönhausen; 1 April 1815 – 30 July 1898) was a German statesman and diplomat who oversaw the unification of Germany and served as its first chancellor from 1871 to 1890. Bismarck's Realpolitik and firm governance resulted in his being popularly known as the Iron Chancellor (Eiserner Kanzler).

From Junker landowner origins, Bismarck rose rapidly in Prussian politics under King Wilhelm I of Prussia. He served as the Prussian ambassador to Russia and France and in both houses of the Prussian parliament. From 1862 to 1890, he held office as the minister president and foreign minister of Prussia. Under Bismarck's leadership, Prussia provoked three short, decisive wars against Denmark, Austria, and France. After Austria's defeat in 1866, he replaced the German Confederation with the North German Confederation, which aligned the smaller North German states with Prussia while excluding Austria. In 1870, Bismarck secured France's defeat with support from the independent South German states before overseeing the creation of a unified German Empire under Prussian rule. Following Germany's unification, he was given the aristocratic title Prince of Bismarck (Fürst von Bismarck). From 1871 onwards, his balance-of-power approach to diplomacy helped maintain Germany's position in a peaceful Europe. While averse to maritime colonialism, Bismarck acquiesced to elite and popular opinion by acquiring colonies.

The Unification of Germany (German: Deutsche Einigung, pronounced [ˈdɔʏtʃə ˈʔaɪnɪɡʊŋ] ) was a process of building the first nation-state for Germans with federal features based on the concept of Lesser Germany (one without the Habsburgs' multi-ethnic Austria or its German-speaking part). After the deletion of the German Confederation due to the Austro-Prussian War, it commenced on 18 August 1866 with the adoption of the North German Confederation Treaty establishing the North German Confederation, initially a military alliance de facto dominated by the Kingdom of Prussia which was subsequently deepened through adoption of the North German Constitution.

The process symbolically concluded when most of the south German states joined the North German Confederation with the ceremonial proclamation of the German Empire (German Reich) having 25 member states and led by the Kingdom of Prussia of Hohenzollerns on 18 January 1871; the event was typically celebrated as the date of the German Empire's foundation, although the legally meaningful events relevant to the completion of unification occurred on 1 January 1871 (accession of South German states and constitutional adoption of the name "German Empire"), 4 May 1871 (entry into force of the permanent Constitution of the German Empire) and 10 May 1871 (Treaty of Frankfurt and recognition of the Empire by the French Third Republic).

The Austro-Prussian War (German: Preußisch-Österreichischer Krieg) was fought in 1866 between the Austrian Empire and the Kingdom of Prussia, with each also being aided by various allies within the German Confederation. Prussia had also allied with the Kingdom of Italy, linking this conflict to the Third Independence War of Italian unification. The Austro-Prussian War was part of the wider rivalry between Austria and Prussia, and resulted in Prussian dominance over the German states, having confirmed Prussia's superior military organization and technology compared to Austria at the time.

The major result of the war was a shift in power among the German states away from Austrian and towards Prussian hegemony. It resulted in the abolition of the German Confederation and its partial replacement by the unification of all of the northern German states in the North German Confederation that excluded Austria and the other southern German states, a Kleindeutsches Reich. The war also resulted in the Italian annexations of the Austrian realm of Venetia.

The Italo-Prussian Alliance was a military pact signed by the Kingdom of Italy and the Kingdom of Prussia on 8 April 1866. It established the terms on which the two nations would enter hostilities against Austria and their respective compensations in the event of victory. For Italy, this was to be the Veneto; for Prussia, other territories of Austria. The alliance led to the Austro-Prussian War which on the Italian front took the name of Third Italian War of Independence. At the end of the conflict, thanks to Prussia's victories, Italy obtained the Veneto while Prussia placed itself at the head of the new North German Confederation.

The proclamation of the German Empire, also known as the Deutsche Reichsgründung, took place on January 18, 1871 after the joint victory of the German states in the Franco-Prussian War. As a result of the November Treaties of 1870, the southern German states of Baden, Hesse-Darmstadt, with their territories south of the Main line, Württemberg and Bavaria, joined the Prussian-dominated "North German Confederation" on 1 January 1871. On the same day, the new Constitution of the German Confederation came into force, thereby significantly extending the federal German lands to the newly created German Empire. The Day of the founding of the German Empire, January 18, became a day of celebration, marking when the Prussian King William I was proclaimed German Emperor at the Palace of Versailles, outside Paris, France.

The Duchy of Brunswick (German: Herzogtum Braunschweig) was a historical German state that ceased to exist in 1918. Its capital was the city of Brunswick (Braunschweig). It was established as the successor state of the Principality of Brunswick-Wolfenbüttel by the Congress of Vienna in 1815. In the course of the 19th-century history of Germany, the duchy was part of the German Confederation, the North German Confederation and from 1871 the German Empire. It was disestablished after the end of World War I, its territory incorporated into the Weimar Republic as the Free State of Brunswick.

The Grand Duchy of Oldenburg (German: Großherzogtum Oldenburg, also known as Holstein-Oldenburg) was a grand duchy within the German Confederation, North German Confederation and German Empire, that consisted of three widely separated territories: Oldenburg, Eutin and Birkenfeld. It ranked tenth among the German states, had one vote in the Bundesrat, and three members in the Reichstag. Its ruling family, the House of Oldenburg, also came to rule in Denmark, Norway, Sweden, Greece, Russia and United Kingdom.