the capital of the Duchy. The in Düsseldorf's coat of arms still points to the historical affiliation of Düsseldorf to the Bergisches Land.

The northern parts of the Bergisches Land included the cities of Mülheim an der Ruhr, parts of Duisburg, Essen and Oberhausen ( and ), and the areas on the western border also included the area on the right bank of the Rhine, Cologne near Mülheim.