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,
History of Cologne In 1074 the commune was formed. By the 13th century, the relationship between the city and its archbishop had become difficult, and after the Battle of Worringen in 1288, the forces of Brabant and the citizenry of Cologne captured Archbishop Siegfried of Westerburg (1274–97), resulting in almost complete freedom for the city. To regain his liberty the archbishop recognized the political independence of Cologne but reserved certain rights, notably the administration of justice. Cologne effectively became a free city after 1288, and in 1475 it was formally made a free imperial city, a status that it held until annexed by