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
Cologne City Hall gradually changed from a mainly feudal society to free citizens. Documents from the years 1135 and 1152, recorded "a house in which citizen convene", referring to the first established council hall, at the location of today's town hall. The coat of arms of Cologne, first mentioned in 1114, is Europe's oldest municipal coat of arms. By 1180, the citizens of Cologne won a legal battle against Philip I, Archbishop of Cologne, for another extension of Cologne's city walls. With the Battle of Worringen fought in 1288, Cologne became independent from the Electorate and on 9. September 1475 officially gained Imperial