In 1288 the Archbishop of Cologne Siegfried von Westerburg was defeated in the Battle of Worringen, and the archbishopric of Kempen, which represented the northern branch of the Archdiocese of Cologne, was threatened from several sides.
That is why Kempen was fortified from around 1290 - initially only with an earth wall that was reinforced with palisades and a ditch. The ardent zeal of the Kempeners in the fortification work was rewarded shortly afterwards with the award of city rights.
Between 1270 and 1320 the final fortification was built. An 1830-meter-long wall enclosed the city in an almost circular manner, broken up by four gates. Four higher towers are said to have been built in connection with the first wall. As the curtain wall grew, an additional 16 semicircular towers were placed in front of it, which ended in a straight line on the city side with the course of the wall. - The material for building the wall was made of bricks that were burned in the Peschbenden between Vorster Strasse and Peschweg and on the Ziegelheide west of Kempen.
Two moats closed off the Kempener Rundling, as the city area was later called, from the outside. - At the end a windmill was placed on the wall.