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,
Historical Archive of the City of Cologne of photographs on the history of art, architecture, culture and photography in Cologne and the Rhineland. The plan was to build the “safest and state-of-the-art city archive in Europe“ by 2017. After the decision of the city council, a detailed concept was worked out and approved. In 2013, in the context of the city's financial crisis, local political debate began to move towards re-considering this decision, and even to imposing a planning moratorium. Protests by local support groups as well as national archive organizations followed. In 2017, the total damage from the collapse was estimated at 1.2 billion euros. Before