The German Empire (German: Deutsches Kaiserreich) is the common name given to the state officially named the Deutsches Reich (literally: "German Realm"), designating Germany from the unification of Germany and proclamation of Wilhelm I as German Emperor on 18 January 1871, to 1918, when it became a federal republic after defeat in World War I and the abdication of the Emperor, Wilhelm II.

The German Empire consisted of 27 constituent territories (most of them ruled by royal families). While the Kingdom of Prussia contained most of the population and most of the territory of the Reich; the Prussian leadership became supplanted by German leaders and Prussia itself played a lesser role. As Dwyer (2005) points out, Prussia's "political and cultural influence had diminished considerably" by the 1890s. Its three largest neighbors were rivals Imperial Russia to the east and France to the west and ally Austria-Hungary to the south.

After 1850, Germany industrialized rapidly, with a foundation in coal, iron (and later steel), chemicals and railways. From a population of 41 million people in 1871, it grew to 68 million in 1913. From a heavily rural nation in 1815, it was now predominantly urban. During its 47 years of existence, the German Empire operated as an industrial, technological and scientific giant, receiving more Nobel Prizes in science than Britain, France, Russia and the United States combined.

Germany (ⁱ/ˈdʒɜrməni/), officially the Federal Republic of Germany (German: Bundesrepublik Deutschland, pronounced [ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant] ( listen)), is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km² and has a largely temperate seasonal climate. With 81.8 million inhabitants, it is the most populous member state and the largest economy in the European Union. It is one of the major political powers of the European continent and a technological leader in many fields.

A region named Germania, inhabited by several Germanic peoples, was documented before AD 100. During the Migration Period, the Germanic tribes expanded southward, and established successor kingdoms throughout much of Europe. Beginning in the 10th century, German territories formed a central part of the Holy Roman Empire. During the 16th century, northern German regions became the centre of the Protestant Reformation while southern and western parts remained dominated by Roman Catholic denominations, with the two factions clashing in the Thirty Years' War, marking the beginning of the Catholic–Protestant divide that has characterized German society ever since. Occupied during the Napoleonic Wars, the rise of Pan-Germanism inside the German Confederation resulted in the unification of most of the German states into the German Empire in 1871 which was Prussian dominated. After the German Revolution of 1918–1919 and the subsequent military surrender in World War I, the Empire was replaced by the Weimar Republic in 1918, and partitioned in the Treaty of Versailles. Amidst the Great Depression, the Third Reich was proclaimed in 1933. The latter period was marked by Fascism and World War II. After 1945, Germany was divided by allied occupation, and evolved into two states, East Germany and West Germany. In 1990 Germany was reunified.