The History of Cologne covers over 2000 years of urban history. In the year 50, Cologne was elevated to a city under Roman law and named "Colonia Claudia Ara Agrippinensium"; since the Frankish rule it is known as Cologne. The city became an influential merchant stronghold in the early Middle Ages due to its location on the Rhine, which allowed the most seasoned Cologne wholesalers to control the flow of goods from northern Italy to England. The archbishops promoted the perception of "Holy Cologne" when they developed the city to the capital of their Electorate of Cologne; to this end, they had both the semicircular city wall and the Gothic cologne cathedral built as a demonstration of power. In the 15th century, Cologne was able to shake off archiepiscopal rule and, as a Free Imperial City, enabled the burgher ruling class to achieve great splendor, visibly documented by the Cologne School of Painting. After the Thirty Years' War, however, the city's development stalled. Only after French occupation when in 1815, Cologne was incorporated into Prussia, the city experienced a steady upswing borne by industrialization. In 1880, the cathedral was completed as a national monument of German imperial unity providing the city with its well-known landmark. Extensive devastation in the Second World War was followed by decades of reconstruction, which only slowly restored Cologne to its emblematic urban panorama on the Rhine through the efforts of urban repair. Today with more than one million inhabitants, Cologne is the fourth largest city in Germany. It is primarily marketed as an event city, with Cologne Carnival being perceived as the biggest tourist attraction.

Colonia Claudia Ara Agrippinensium was the Roman colony in the Rhineland from which the city of Cologne, now in Germany, developed.