Berlin is the capital and largest city of Germany. With 3.7 million inhabitants, it has the highest population within its city limits of any city in the European Union (EU). The metropolis is also one of the states of Germany, being the third-smallest state in the country by area. Berlin is surrounded by the state of Brandenburg, bordering Brandenburg's capital Potsdam to the southwest. The urban area of Berlin has a population of 4.5 million, making it the second most populous in Germany after the Ruhr. The Berlin-Brandenburg capital region has around 6.2 million inhabitants and is Germany's second-largest metropolitan region after the Rhine-Ruhr region, as well as the fifth-biggest metropolitan region by GDP in the EU. Berlin is a global city of culture, politics, media and science.
Berlin was built along the banks of the Spree river, which flows into the Havel in the western borough of Spandau. First documented in the 13th century and at the crossing of two important historic trade routes, Berlin was designated the capital of the Margraviate of Brandenburg (1417–1701), Kingdom of Prussia (1701–1918), German Empire (1871–1918), Weimar Republic (1919–1933), and Nazi Germany (1933–1945). Berlin served as a scientific, artistic, and philosophical hub during the Age of Enlightenment, Neoclassicism, and the German revolutions of 1848–1849. During the Gründerzeit, an industrialization-induced economic boom triggered a rapid population increase in Berlin. Berlin in the 1920s was the third-largest city in the world by population.
After World War II and following Berlin's occupation, the city was split into West Berlin and East Berlin, divided by the Berlin Wall. East Berlin was declared the capital of East Germany, while Bonn became the West German capital. Following German reunification in 1990, Berlin once again became the capital of all of Germany. Due to its geographic location and history, Berlin has been called "the heart of Europe". Its economy is based on high tech and the service sector, encompassing a diverse range of creative industries, startup companies, research facilities, and media corporations. Berlin serves as a continental hub for air and rail traffic and has a complex public transportation network. Tourism in Berlin makes the city a popular global destination.
Berlin is home to several universities, such as the Humboldt University of Berlin, Technische Universität Berlin, the Berlin University of the Arts and the Free University of Berlin. The Berlin Zoological Garden is the most visited zoo in Europe. Babelsberg Studio is the world's first large-scale movie studio complex, and there are many films set in Berlin. Berlin is home to three UNESCO World Heritage Sites: Museum Island, the Palaces and Parks of Potsdam and Berlin, and the Berlin Modernism Housing Estates. Other landmarks include the Brandenburg Gate, the Reichstag building, Potsdamer Platz, the Memorial to the Murdered Jews of Europe, and the Berlin Wall Memorial. Berlin has numerous museums, galleries, and libraries. The city includes lakes in the western and southeastern boroughs, the largest of which is Müggelsee. About 1/3 of the city's area is composed of forests, parks and gardens, rivers, canals, and lakes.
Berlin lies in northeastern Germany, in an area formerly settled by Slavs which thus exhibits many (Germanized) Slavic-derived placenames to this day (see below). The word Berlin also has its roots in the language of the West Slavs, and may be related to the Old Polabian stem berl-/birl- ("swamp").
Of Berlin's twelve boroughs, five bear a Slavic-derived name—Pankow, Steglitz-Zehlendorf, Marzahn-Hellersdorf, Treptow-Köpenick and Spandau; furthermore, across the city's 96 neighborhoods, there are 22 which bear a Slavic-rooted name—Altglienicke, Alt-Treptow, Britz, Buch, Buckow, Gatow, Karow, Kladow, Köpenick, Lankwitz, Lübars, Malchow, Marzahn, Pankow, Prenzlauer Berg, Rudow, Schmöckwitz, Spandau, Stadtrandsiedlung Malchow, Steglitz, Tegel and Zehlendorf.
The area of what is now Berlin has been settled for millennia. A deer mask, dated to 9,000 BCE, is attributed to the Maglemosian culture. Around 2,000 BCE dense human settlements along the Spree and Havel rivers gave rise to the Lusatian culture. Starting around 500 BCE Germanic tribes settled in a number of villages in the higher situated areas of today's Berlin. After the Semnones left around 200 CE, the Burgundians followed. In the 7th century Slavic tribes, the later known Hevelli and Sprevane, reached the region.
In the 12th century the region came under German rule as part of the Margraviate of Brandenburg, founded by Albert the Bear in 1157. The first written records of towns in the area of present-day Berlin date from the late 12th century. Spandau is first mentioned in 1197 and Köpenick in 1209. German merchants founded two settlements in today's city center – Berlin (or Alt-Berlin; at the site of today's Nikolaiviertel) and Cölln (on the island in the Spree now known as Museum Island). 1237 is considered the founding date of the city. Berlin and Cölln over time formed close economic and social ties, and profited from the staple right on the two important trade routes. One was known as Via Imperii, and the other trade route reached from Bruges to Novgorod. In 1307, the two towns formed an alliance with a common external policy, their internal administrations still being separated. In 1326, the territory of Berlin was raided by pagan Lithuanians during the Raid on Brandenburg.
Members of the Hohenzollern family ruled in Berlin until 1918, first as electors of Brandenburg, then as kings of Prussia, and eventually as German emperors. In 1443, Frederick II of Brandenburg initiated the construction of a new royal palace in the twin city of Berlin-Cölln. The protests of the town citizens against the building culminated in 1448, in the "Berlin Indignation" (German: Berliner Unwille). Officially, the Berlin-Cölln palace became the permanent residence of the Brandenburg electors of the Hohenzollern dynasty in 1486, when John Cicero took power. Berlin-Cölln, however, had to give up its status as a free Hanseatic League city. In 1539, the electors and the city officially became Lutheran.
The Thirty Years' War between 1618 and 1648 devastated Berlin. One third of its houses were damaged or destroyed, and the city lost half of its population. Frederick William, known as the "Great Elector", who had succeeded his father George William as ruler in 1640, initiated a policy of promoting immigration and religious tolerance. With the Edict of Potsdam in 1685, Frederick William offered asylum to the French Huguenots.
By 1700, approximately 30 percent of Berlin's residents were French, because of the Huguenot immigration. Many other immigrants came from Bohemia, Poland, and Salzburg.
Since 1618, the Margraviate of Brandenburg had been in personal union with the Duchy of Prussia. In 1701, the dual state formed the Kingdom of Prussia, as Frederick III, Elector of Brandenburg, crowned himself as king Frederick I in Prussia. Berlin became the capital of the new Kingdom, replacing Königsberg. This was a successful attempt to centralise the capital in the very far-flung state, and it was the first time the city began to grow. In 1709, Berlin merged with the four cities of Cölln, Friedrichswerder, Friedrichstadt and Dorotheenstadt under the name Berlin, "Haupt- und Residenzstadt Berlin". Between 1700 and 1750, Berlin's population nearly quadrupled, rising from about 30,000 to 113,000.
In 1740, Frederick II, known as Frederick the Great (1740–1786), came to power. Under the rule of Frederick II, Berlin became a center of the Enlightenment, but also, was briefly occupied during the Seven Years' War by the Russian army. Following France's victory in the War of the Fourth Coalition, Napoleon Bonaparte marched into Berlin in 1806, but granted self-government to the city. In 1815, the city became part of the new Province of Brandenburg.
The Industrial Revolution transformed Berlin during the 19th century; the city's economy and population expanded dramatically, and it became the main railway hub and economic center of Germany. Additional suburbs soon developed and increased the area and population of Berlin. In 1861, neighboring suburbs including Wedding, Moabit and several others were incorporated into Berlin. In 1871, Berlin became capital of the newly founded German Empire. In 1881, it became a city district separate from Brandenburg.