History of Cologne City Archive, which was the largest in Germany. Its building collapsed during the construction of an extension to the underground railway system on 3 March 2009. History of Cologne The German city of Cologne was founded in the 1st century as the Roman Colonia Claudia Ara Agrippinensium. It was taken by the Franks in the 5th century and became an important city of Medieval Germany, the seat of an Archbishop and a Prince-Elector. As the Free Imperial City of Cologne it was one of the centers of the Hanseatic League in the early modern period. Most of the city was
Historical Archive of the City of Cologne the 1897 building has been used as a private library by Gerling, a large insurance company. In 1971, a six-story archive building by architect Fritz Haferkamp was built on Severinstraße in the southern part of Cologne's city center. An underlying principle of the design was to protect archival records from fluctuations in weather and climate while creating a balanced room climate. In a move away from the contemporary popularity of electromechanical air conditioning, Haferkamp preferred a structural-physical, self-regulating solution that needed only little additional climate technology. As the "Cologne Model", the building became a model for many later archive buildings