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,
Demographics of Cologne over the old city walls in 1794, just short before the arrival of French troops and Cologne's incorporation into the First French Empire. After 1815, the Kingdom of Prussia enforced the construction of fortifications which again hindered any growth for the city. Only with the acquisition of these fortifications in 1881, the city of Cologne had the possibility of a gradual territorial expansion. On 12. November 1883 a strip of territory from parts of the municipalities of Ehrenfeld, Kriel, Longerich, Müngersdorf and Rondorf was added to the city. Since 1886, the Cologne City Council intensified negotiations with the surrounding communities,