In 1529 a castle was built on the spot where the pond is. In the 1940s remnants of the ancient château were found in the pond.
The castle known as "Losange", was built in the early 1700s by Herman de Trappé. Many generations later it was used as a summer residence by count Frédérik "Fritz" van den Steen de Jehay, who was married to baroness Henriette Snoy, one of queen Elisabeth's ladies-in-waiting. During the 1920s and 1930s she had the castle modernized to the look it has today.
Count Fritz died in 1918 when he fell from his horse. His widow kept on using Losange untill she died in 1957. As an intimate of Belgian court, she let the royals enjoy her château in the Ardennes. In 1926 crown prince Léopold stopped by.
In 1928 Léopold made another visit, accompanied by his wife, crown princess Astrid and his sister, princess Marie-José.
Marie José even used the spot for a private celebration of her engagement to Italian crown prince Umberto in 1929.
In 1972 Patrick married the Polish countess Anna Komorowska and together they undertook a thorough restauration of their castle, which had been uninhabited since 1957.
Their 5 children grew up in the castle and on the estate. Anna's parents lived closeby, in the village of Honville.
The different rooms of the castle all have a name: la chambre du Vicaire, du Cardinal, de la Comtesse ... Mathilde's room was above the chapel and was called 'la lingerie'.
Scouting groups were allowed to camp on the grounds of the Losange estate. Mathilde used to bring them their mail from home, by bike.