Bonn Minster is a Roman Catholic church in Bonn. It is one of Germany's oldest churches, having been built between the 11th and 13th centuries. At one point the church served as the de-facto cathedral for the Archbishopric of Cologne, because it is the major church of what was then the Archbishop-Elector's residence. It is now a minor basilica. It served as the inspiration for the Kaiser Wilhelm Memorial Church in Berlin, as Kaiser Wilhelm II had studied in Bonn.