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 libraries that did not suffer major losses during the French occupation in the early years of the 19th century. After the secularization of abbeys and colleges of canons in Cologne in the early years of the 19th century, the French government ordered their archives to be stored in the state archives in Düsseldorf. It was not until 1949 that a mayor of Cologne succeeded in recovering 19,000 charters and many other records for the Cologne municipal archives. In 1818, the city of Cologne was bequeathed Ferdinand Franz Wallraf's major collection of art, books and manuscripts. After Wallraf's death in 1824,