Cologne – 2,000 years on the Rhine

Officially the building is called Hohe Domkirche zu Köln. The Roman Catholic church is dedicated to the Apostle Peter and serves as the cathedral of the Archdiocese of Cologne as well as the metropolitan church of the ecclesiastical province of Cologne; its head is the cathedral provost. At a height of 157.22 metres, the cathedral is the fourth-tallest church in the world and, after Ulm Minster, the second-tallest sacred building in Germany.

The Gothic construction began in 1248 on the commission of Konrad I after a design by Master Gerhard and was completed only in 1880 on the commission of Friedrich Wilhelm IV following plans by Ernst Friedrich Zwirner. The church was conceived as the cathedral of the Cologne archbishops and as a reliquary for the remains of the Three Magi. On its completion in the 19th century it was regarded as a national symbol for Germany; after the Second World War the largely preserved structure amid the destroyed city was interpreted as a sign of the will to live.

The present cathedral has a long prehistory. Maternus, a confidant of Emperor Constantine I, is attested around 313 as the first bishop of Cologne. The early Christian community initially gathered in dwellings, one of them probably on the cathedral hill beneath today's choir, near the Rhine at the northern edge of the settlement. A baptismal basin excavated there, dating from the 5th century, is regarded as the oldest evidence of Christian worship in Cologne. In the 6th century the Merovingian kings erected a church 40 to 50 metres long at this site, which also served as a royal burial place.

In the Carolingian period the so-called Hildebold Cathedral was built, consecrated in 870, and at around 95 metres one of the largest churches of its era. As a basilica with two choirs, the eastern choir was dedicated to Mary and the western to Peter; with reference to Old St Peter's in Rome it was regarded as the Peter's church of the North. In 1164 Archbishop Rainald von Dassel brought the remains of the Three Magi from Milan to Cologne, for which the Shrine of the Three Kings was produced between 1190 and 1225. The city thereby became a place of pilgrimage.

With the start of construction of the Gothic cathedral in 1248, the Old Cathedral was to be dismantled; however, a fire during the demolition work largely destroyed it, though the shrine could be saved. Archbishop Konrad von Hochstaden laid the foundation stone on 15 August 1248. Master builder Gerhard designed a choir with a wreath of seven chapels, using trachyte from the Drachenfels as building material. In 1265 the chapel wreath was completed and used as a burial place; in 1277 Albertus Magnus consecrated the associated altar. The completion of the high choir was in the hands of master builder Arnold from 1271; around 1304 the choir was closed off to the west by a dividing wall that remained until 1863.

Cologne's municipal area covers 405.01 square kilometres, of which 230.25 lie on the left bank of the Rhine and 174.87 on the right. The city sits in the Cologne Bay, a funnel-shaped river-valley landscape that the Rhine has shaped immediately after leaving the Rhenish Slate Mountains, between the slopes of the Bergisches Land and the Eifel. The highest point is the Monte Troodelöh in the Königsforst at 118.04 metres, the lowest lies at 37.5 metres above sea level in the Worringer Bruch. The tip of the northern cathedral tower serves as the topographical reference point.

After emerging from the slate mountains south of the city, the Rhine is referred to as the Lower Rhine. It reaches Cologne at Godorf and leaves it at Worringen; its gradient is about 0.2 per mille. The current water level can be read from the clock of the Cologne gauge, which shows 3.48 metres at normal water, corresponding to a depth of roughly 4.48 metres in the navigation channel.

The city was struck by floods several times. The most severe recorded event occurred in February 1784: after the long, cold winter of 1783/84 the Rhine had frozen over, and the onset of the snowmelt together with the breaking ice led to a record level of 13.55 metres. Drifting ice floes devastated the riverside buildings and all vessels, destroyed individual structures and claimed 65 lives. Mülheim am Rhein, situated on the right bank and today a district of Cologne, was completely destroyed.

In the 20th century the major floods of 1926, 1993 and 1995 reached levels of up to 10.69 metres. Since 2005 a flood-protection concept has been implemented that shields the city with fixed and mobile walls up to a gauge level of 11.90 metres.

Low water also occurred: on 20 September 2003 the gauge fell to 0.8 metres at 8 a.m., dropping below the value of 1947. This low was undercut again in October 2018, when only 0.67 metres were measured on 23 October. A gauge reading of 0 metres, however, means that the 150-metre-wide navigation channel in the middle of the river still holds one metre of water; inland shipping had to accept restrictions but was not halted as it was on the Elbe.

How much the water volumes differ according to the gauge level is shown by the figures: at 0.80 metres about 630 cubic metres per second flow through the city, at the normal level of 3.48 metres around 2,000, at 6.20 metres (flood mark I) 4,700, at 8.30 metres (flood mark II) 7,200, and during the January 1995 flood at 10.69 metres roughly 11,500 cubic metres per second. As of 2020, 63 per cent of the inhabitants live on the left bank; since the historic centre lies there, the right side is colloquially called the "Schäl Sick".

Cologne is one of Germany's most important media cities: broadcasters, production companies and publishers are based here, alongside a strong insurance and trading sector.

Koelnmesse is one of the largest exhibition grounds in the world. Leading fairs such as the gamescom video-game show, the Anuga food fair and Art Cologne draw hundreds of thousands of trade visitors every year.

Cologne is also a central transport hub – with its main station right beside the cathedral, inland ports on the Rhine and Cologne Bonn Airport to the south.

The University of Cologne was founded in 1388, making it one of the oldest universities in Central Europe; today it is one of Germany's largest. Alongside it, many specialised colleges shape the picture: TH Köln, the German Sport University, the University of Music and Dance and the Academy of Media Arts.

There are also private and church-run institutions such as the Rheinische Hochschule, CBS International Business School and the Catholic University of Applied Sciences.

Together, over 90,000 students make Cologne a young, lively university city – with a matching offer of culture, nightlife and creativity across the quarters.