sentences:  Around 1424, Eberhard II von der Mark built a manor with two towers around a church over a period of six years.When Eberhard died in 1440, his son Jean de la Marck began reinforcing the fortress, but it was Robert II de la Marck, the grandson of Jean, who finished the most important work.In 1530, the fortifications of the manor were modernised by the construction of a circular boulevard and terraces with cannons, thickening the curtain wall by an additional .