Historical Archive of the City of Cologne included copies of the protocols of the diets of the Hanseatic League. With the 1594 transfer, the Cologne archive became the most important repository of historical material concerning the Hanseatic League and thus concerning the history of Northern Germany in general, only matched by the municipal archives of Lübeck. On 27 February 1602, the city council ordered that books on jurisdiction and administration were to be systematically bought at the regularly held Frankfurt Book Fair. These were subsequently stored in the municipal archive and became the basis of the Cologne municipal library. The "Ratsbibliothek" was one of the few Cologne
Districts of Cologne while maintaining close economic links to the city of Cologne. More than half of the estates here were in the hands of citizens of Cologne or the same becoming residents in these areas. Since 1886, the Cologne City Council intensified negotiations with the surrounding communities, and on 1 April 1888 ended in a first major incorporation. Since then the city has expanded with major reorganizations in 1910, 1914, 1922 and 1975. Districts of Cologne Since the last administrative reform in 1975, the City of Cologne is made up of nine Stadtbezirke and 86 Stadtteile. "Stadtbezirk" literally translates as city district,