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 municipal archive and library was erected between 1894 and 1897 to a Gothic revival design by Friedrich Carl Heimann: it was inaugurated in December 1897. The new building was large enough to accommodate the archive at a time of accelerated growth when the city of Cologne was absorbing many previously independent towns and villages. During World War II the building suffered damage from bombing. However, since all records and manuscripts had been moved into secure storage from as early as September 1939, the archive did not suffer any substantial loss. Since the archive moved to its new location in 1971,