Ruhr in the context of "Rhine"

A conurbation is a region consisting of a number of metropolises, cities, large towns, and other urban areas which, through population growth and physical expansion, have merged to form one continuous urban or industrially developed area. In most cases, a conurbation is a polycentric urbanised area in which transportation has developed to link areas. They create a single urban labour market or travel to work area.

Conurbations often emerged in coal-mining regions during the period of the Industrial Revolution.Patrick Geddes coined the term in his book Cities in Evolution (1915). He drew attention to the ability of the new technology at the time of electric power and motorised transport to allow cities to spread and agglomerate together, and gave as examples "Midlandton" in England, the Ruhr in Germany, Randstad in the Netherlands, and the Northeastern Seaboard in the United States.

The Rhine-Ruhr metropolitan region (German: Metropolregion Rhein-Ruhr) is the largest metropolitan region in Germany, with over ten million inhabitants. A polycentric conurbation with several major urban concentrations, the region covers an area of 7,110 square kilometres (2,750 sq mi), entirely within the federal state of North Rhine-Westphalia. The Rhine-Ruhr metropolitan region spreads from the Ruhr area (Dortmund-Bochum-Essen-Duisburg) in the north to the urban areas of the cities of Mönchengladbach, Düsseldorf (the state capital), Wuppertal, Leverkusen, Cologne (the region's largest and Germany's fourth largest city), and Bonn in the south. The location of the Rhine-Ruhr at the heart of the European Blue Banana makes it well connected to other major European cities and metropolitan areas such as the Randstad, the Flemish Diamond and the Frankfurt Rhine Main Region.

The metropolitan area is named after the Rhine and Ruhr rivers, which are the region's defining geographical features and historically its economic backbone.

Germany, officially the Federal Republic of Germany, is a country in Western and Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen constituent states have a total population of over 83 million, making it the most populous member state of the European Union. Germany borders Denmark to the north; Poland and the Czech Republic to the east; Austria and Switzerland to the south; and France, Luxembourg, Belgium, and the Netherlands to the west. The nation's capital and most populous city is Berlin and its main financial centre is Frankfurt; the largest urban area is the Ruhr.

Settlement in the territory of modern Germany began in the Lower Paleolithic, with various tribes inhabiting it from the Neolithic onward, chiefly the Celts, with Germanic tribes inhabiting the north. Romans named the area Germania. In 962, the Kingdom of Germany formed the bulk of the Holy Roman Empire. During the 16th century, northern German regions became the centre of the Protestant Reformation. Following the Napoleonic Wars and the dissolution of the Holy Roman Empire in 1806, the German Confederation was formed in 1815.

The Bergisches Land (German pronunciation: [ˈbɛʁɡɪʃəs ˈlant], lit. 'Bergian Land') is a low mountain range in the state of North Rhine-Westphalia, Germany, east of the Rhine and south of the Ruhr. The landscape is shaped by forests, meadows, rivers and creeks and contains over twenty artificial lakes. Wuppertal is the biggest town, while the southern part has economic and socio-cultural ties to Cologne. Wuppertal and the neighbouring cities of Remscheid and Solingen form the Bergisches Städtedreieck (Berg City Triangle).

Duisburg (German: [ˈdyːsbʊʁk] ; Low German: Duisborg, pronounced [ˈdʏsbɔɐ̯χ]) is a major city in the western part of Germany, located in the state of North Rhine-Westphalia. With around half a million inhabitants, it is one of the largest cities in the Ruhr urban area and part of the larger Rhine-Ruhr metropolitan region, one of the biggest population centers in Europe. Duisburg is situated at the confluence of the Ruhr and the Rhine, a geographic position that has historically made it an important center of trade, industry, and transportation. Administratively, Duisburg forms an independent city (kreisfreie Stadt).

The city is known for hosting the world's largest inland port, the Port of Duisburg [de], which plays a key role in European logistics and international trade. The port's facilities are directly linked to major motorways, rail networks, and the Rhine waterway, connecting Duisburg to the North Sea and beyond. Today, Duisburg is a hub for the steel, chemical, and logistics industries, and it has also become an important node in trade relations with China, being a key terminus for freight trains on the Chongqing–Xinjiang–Europe railway.

Mülheim, officially Mülheim an der Ruhr (German pronunciation: [ˈmyːlhaɪm ʔan deːɐ̯ ˈʁuːɐ̯] , lit. 'Mülheim on the Ruhr'; Low German: Mölm; Kölsch: Müllem) and also described as "City on the River", is a city in North Rhine-Westphalia in western Germany. It is located in the Ruhr Area between Duisburg, Essen, Oberhausen and Ratingen. It is home to many companies, and two Max Planck Institutes.

Mülheim an der Ruhr was granted city rights in 1808, and a century later its population surpassed 100,000, officially making it a major city.”

Essen (German pronunciation: [ˈɛsn̩] ) is the central and, after Dortmund, second-largest city of the Ruhr, the largest urban area in Germany. Its population of 574,082 makes it the fourth-largest city of North Rhine-Westphalia after Cologne, Düsseldorf and Dortmund, as well as the tenth-largest city of Germany. Essen lies in the larger Rhine-Ruhr metropolitan region, second largest by GDP in the EU, and is part of the cultural area of Rhineland. Due to its central location in the Ruhr, Essen is often regarded as the Ruhr's "secret capital".

Two rivers flow through the city: the Emscher in the north, and in the south the Ruhr River, which is dammed in Essen to form the Lake Baldeney [de] and Lake Kettwig [de] reservoirs. The central and northern boroughs of Essen historically belong to the Low German Westphalian dialects area, and the south of the city to the Low Franconian Bergish area.

Gelsenkirchen (/ˌɡɛlzənˈkɪərxən/, /ˈɡɛlzənkɪərxən/; German: [ˌɡɛlzn̩ˈkɪʁçn̩] ; Westphalian: Gelsenkiärken) is the 25th-most populous city of Germany and the 11th-most populous in the state of North Rhine-Westphalia with 262,528 (2016) inhabitants. On the Emscher River (a tributary of the Rhine), it lies at the centre of the Ruhr area, the largest urban area of Germany, of which it is the fifth-largest city after Dortmund, Essen, Duisburg and Bochum. The Ruhr is located in the Rhine-Ruhr metropolitan region, the second-biggest metropolitan region by GDP in the European Union. Gelsenkirchen is the fifth-largest city of Westphalia after Dortmund, Bochum, Bielefeld and Münster, and it is one of the southernmost cities in the Low German dialect area. The city is home to the football club Schalke 04, which is named after Gelsenkirchen-Schalke. The club's current stadium Veltins-Arena, however, is located in Gelsenkirchen-Erle [de].

Gelsenkirchen was first documented in 1150, but it remained a tiny village until the 19th century, when the Industrial Revolution led to the economic and population growth of the region. In 1840, when the mining of coal began, 6,000 inhabitants lived in Gelsenkirchen; by 1900 the population had increased to 138,000. In the early 20th century, Gelsenkirchen was the most important coalmining town in Europe. It was called the "city of a thousand fires" for the flames of mine gases flaring at night. In 1928, Gelsenkirchen was merged with the adjoining cities of Buer and Gelsenkirchen-Horst [de]. The city bore the name Gelsenkirchen-Buer, until it was renamed Gelsenkirchen in 1930. The city remained a center of coal mining and oil refining during the Nazi era, so was often a target of Allied bombing raids during World War II: nevertheless, over a third of the city's buildings date from before 1949. There are no longer coalmines in and around Gelsenkirchen; the city is searching for a new economic basis, having been afflicted for decades with one of the country's highest unemployment rates.