The town of Barntrup was founded around 1300 by the Counts of Sternberg. At this time at the latest there must have been a castle. Between 1584 and 1588 the Kerssenbrock Castle was built on the lower courtyard in the style of the Weser Renaissance.
Here, for the first time in Westphalia, a completely new building concept appears: the single standing castle with round corner towers integrated into the building structure. Even if the whole thing looks very defensive, the towers have only a decorative function.
Originally, an additional southwest wing was probably planned, but only the octagonal stair tower was realized. Schloss Barntrup was planned by the same architect as the nearby Schloss Wendlinghausen. However, the façade here is considerably more lavishly structured and decorated.