In the historical map holdings of the ULB, the works of Flemish-Dutch cartographers are a focal point: Willem Blaeuw, Jodocus Hondius, Jan Jansson, Lucas Jacob Waghenaer, and especially Gerhard Mercator. The text printing of their atlases was done in Düsseldorf. In Cologne, an independent cartographic tradition developed in the second half of the 16th century with Johannes Metellus and Matthias Quad, which is also present in the collection. The very accurate maps of the course of the Rhine published at the end of the 18th century by Carl Friedrich von Wiebeking, the Electoral Palatine water engineer in the Duchy of Berg, represent the last high point of the regional cartographic tradition.