Rivalry between Cologne and Düsseldorf, two major cities in the Rhineland, Germany, apart on the Rhine, is now mostly on a sporting and cultural level, but based on historical and economic factors. Cologne was a Roman colony, and later a Free Imperial City, while Düsseldorf, a small medieval settlement, is now the capital of the state of North Rhine-Westphalia. The root of the enmity between the two cities is commonly cited as the Battle of Worringen on 5 June 1288, which, however, is to be regarded as "legend". At this battle, part of the War of the Limburg Succession, Siegfried von Westerburg, then Archbishop of Cologne, lost to John I, Duke of Brabant. Among others, Count Adolf von Berg, the citizens of Cologne and an army of peasants from the Bergisches fought on the side of the Brabant duke. There may also have been some inhabitants of the village in the estuary of the Düssel, but this is not considered certain. While Cologne was already a large medieval city with over 20,000 inhabitants and, as an original Roman foundation, more than 1200 years old, Düsseldorf was a smaller settlement in the County of Berg with an estimated 200 to 400 inhabitants. The inhabitants of the two unequal towns did not fight against each other in this battle, as is often depicted, but side by side. Both places benefited from the outcome of the battle: after the defeat of the archbishop, Cologne no longer belonged to his archbishopric, and the archbishop himself could only enter the city for religious acts. Duke Adolf of Berg granted Düsseldorf city rights on 14 August 1288, though not out of "gratitude", as is rumoured. The ruler had recognised the village's strategic location on a flood-free headland with the Rhine forming a natural safeguard on the western border, seeing the city as a bulwark against the still archiepiscopal and at the time considerably larger Neuss situated on the other side of the river. In the 13th century, Cologne was the "undisputed metropolis of Germany" with trade relations to many European countries, and with a size "of around 20,000–25,000 inhabitants, it was at the top of all German cities".
Wolf Hendrik Huwald, Aurélien Gallice