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
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