Demographics of Cologne and on 1 April 1888 ended in a first major incorporation. The territorial expansion, beginning in the late 19th century, were significant marks for the city's population growth. Major communal reorganizations took place in 1910, 1914, 1922 and 1975. Demographics of Cologne Cologne () is Germany's fourth-largest city and the largest city in the Rhineland. As of 31 December 2011, there were officially 1,017,155 residents. The city is center of the Cologne/Bonn Region with around 3 million inhabitants (including the neighboring cities of Bonn, Hürth, Leverkusen, and Bergisch Gladbach). The walls of Colonia Agrippina covered an area of 96.8 hectares,
Districts of Cologne 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, which are further subdivided into "Stadtteile" (city parts). The Stadtteile of Cologne's old and new town ("Alt-" and "Neustadt") further consist of quarters, known as ""Veedel"" in both Kölsch and most often, the Rhinelandic regiolect, as well. City districts are differentiated of being "links-" or "rechtsrheinisch" – "left" or "right of the Rhine", with the old town being left of the Rhine, as are 230,25 km² (56.8 percent of 405,14 km²