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,
Electorate of Cologne confused with the Roman Catholic Archdiocese of Cologne, which was larger and included suffragant bishoprics such as Liège and Münster over which the Elector-Archbishop exercised only spiritual authority (see map below). Cologne was the ancient Roman city of Colonia Agrippina in the province of Germania Inferior, and has been a bishop's see since Roman times. In 953, the archbishops of Cologne first gained noteworthy secular power, when Bishop Bruno was appointed as duke by his brother Emperor Otto I. To weaken the secular nobility, who threatened his power, Otto endowed Bruno and his successors in the bishop's see with the