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 near the Cologne town hall. The records were for the most part those of real estate transactions: these were recorded on sheets of parchment or in books, which subsequently became known as "Schreinsbücher" (shrine books). In Cologne, these books can be traced back to AD 1130. Similar books from the late 12th century are known from the cities of Metz and Andernach. In the 19th century, all records of the old Cologne shrine quarters were transferred to the municipal archives. A municipal archive has existed since at least the year 1322. In 1326 the city council decided to establish the