History of the Ruhr

The actual boundaries of the Ruhr vary slightly depending on the source, but a good working definition is to define the Lippe and Ruhr as its northern and southern boundaries respectively, the Rhine as its western boundary, and the town of Hamm as the eastern limit.
In the Middle Ages, local power was vested primarily in the counts ("Grafen") of Berg, Mark and Cleves. The left bank of the Rhine was held by the Archbishop of Cologne. The Hellweg was an important trade route crossing the region from Duisburg to Dortmund and beyond as far as the rivers Weser and Elbe. The most important towns of the region were concentrated along the Hellweg.
As a result of the Congress of Vienna, the entire area came under the control of Prussia (the state had already gained possessions there). This event was almost concomitant with developments which would eventually make the region one of the most important industrial areas in the world.
In 1946, the state of North Rhine-Westphalia came into being centred on the Ruhr. Nowadays, its hitherto important coal and steel industries have drastically declined and the region is in a state of re-adjustment.
Carboniferous period.
During the Carboniferous Period, in the Paleozoic era, which began 360 million years ago and ended 300 million years ago, layers of slate, coal and sandstone were formed. 400 to 300 million years ago, new mountains were uplifted during the Variscan mountain-building period.
During the Silesian period, layers were deposited which became seams of coal over a period lasting millions of years. During this period there was a constant shifting between marshy conditions and overflowing seas such that the depositing of plant material and sediment from the sea resulted in the current situation of coal layers separated by stone layers.
The main representatives of flora in the coal marshes were of the genus "Lepidodendron" and genus "Sigillaria", tree-like plants, which belong to the plant classification Lycopodiophyta. Members of both genus reached heights of up to 40 meters with a trunk diameter of over a meter.
Cretaceous Period.
In the Cretaceous, 135 million to about 66 million years ago, the region was submerged under a tropical ocean. In its waters lived ammonites. On the floor of the sea, a thick layer of marl formed. The sediments covered the layers of carbon and contained also the shells of giant ammonites.
Quaternary.
The Ice Age brought changes between warm and cold weather. During the Drenthe Stadium of the Wolstonian Stage, an ice sheet over Northern Germany covered the Ruhr and reached as far as the northern hills of the Central Uplands. The shape of the middle and lower Ruhr valley is due to meltwaters and the powerful force of the ice. Meltwater from the glaciers flowed westwards through the Ruhr valley. Where Essen lies today, this flow was temporarily hindered by a barrier of ice and rocky debris, forming an enormous lake which filled the valley at Schwerte.
Prussian Absolutism.
Large areas of the Ruhr come under Prussian control. Ironworks are started up and coal-mining accelerates. Industry in general receives some direct and indirect encouragement from the Prussian state.
First half of the 19th century – Industrial Revolution.
The Industrial Revolution advances in the Ruhr. At the start of the 19th century, the steam engine is used there for the first time, and Napoleonic measures abolish feudal influences. When the entire area comes under Prussian hegemony in 1815, further advances are made in transportation and encouragement of industry. By the 1830s, the important deep-lying coking-coal seams of the Emscher Basin are reached for the first time, railways make their appearance and in 1849 smelting iron ore with coke is successfully carried out for the first time in the Ruhr.
Second half of the 19th century – industry booms.
The advances made in the first half of the century were built upon, producing a significant advance in production. In 1850, the district produced 2 million tonnes of coal, by 1913 it produced 114 million tonnes. Likewise, in 1850 it produced 11,500 tonnes of cast iron which rose by 1913 to 8.2 million tonnes. Coal production moved northwards as steam engine technology allowed the exploitation of deep coking coal seams (the earlier mines, generally nearer the River Ruhr, had tended to be drift mines exploiting the anthracite lying nearer the surface). 'Vertical' concerns came into being, with collieries, cokeries and ironworks under common ownership, and it was not uncommon to have all constituents located on the same site or close together.
First half of the 20th century (to 1945).
The coal and steel industries continue to expand, with the Ruhr reaching a position whereby its coal and steel production is in each case almost equivalent to the rest of continental Europe put together (excluding the USSR)
The Ruhr industrialist Fritz Thyssen assists the NSDAP with a massive financial sum.
Second Half of the 20th century (from 1946).
Industry in the district is restored after the war, but by the end of the 20th century the coal and steel industries have declined drastically