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.
