Districts of Cologne within city limits), while 174,87 km² (43.2 percent) lie right of the Rhine. In regard to population, Cologne is the largest city in the state of North Rhine-Westphalia and the fourth largest city in Germany. Since the city's foundation in 38 BC, Cologne grew through numerous extensions and incorporation of surrounding municipalities. Since the construction of the Medieval wall in 1180, the area of the old imperial city of Cologne has not changed for more than 600 years and was only extended over the old city walls in 1794, just short before the arrival of French troops and Cologne's incorporation
Districts of Cologne while maintaining close economic links to the city of Cologne. More than half of the estates here were in the hands of citizens of Cologne or the same becoming residents in these areas. Since 1886, the Cologne City Council intensified negotiations with the surrounding communities, and on 1 April 1888 ended in a first major incorporation. Since then the city has expanded with major reorganizations in 1910, 1914, 1922 and 1975. Districts of Cologne Since the last administrative reform in 1975, the City of Cologne is made up of nine Stadtbezirke and 86 Stadtteile. "Stadtbezirk" literally translates as city district,