History of the castle (many thanks to Christian Mersch for the contribution):
400 years ago, the castle of Koerich was the residence of the vice-governor Pierre-Ernest de Raville. When he went to the fortress Luxembourg to do business, he had the "Maison de Raville" (still exists, close to nowadays Palais grand-ducal) as a place to go. De Raville's father was also vice-governor at the time of the famous Pierre-Ernest de Mansfeld. The families of Mansfeld and De Raville had close ties, Pierre-Ernest de Raville was the godfather of one of Mansfeld's illigitimate son's who became an (in)famous warlord in the Thirty Year's War. In the 1630s, croatian mercenary troups terrorised the village of Koerich, already shaken by witch trials.
At the time of the Thirty Year's War, Lorraine was still a duchy apart from France. That region was a major corridor for troup movements in Europe, while Luxembourg was a bit less exposed. It is my comprehension that historic exploration of that war is best approached using Lorraine sources, as complete Luxembourg sources about that time are very scarce.