The Château de Rolleboise was built by Bibi De Wulf. That was her maiden name. She became baronne Vallée-De Wulf after she married. As is the custom in France and Belgium, her maiden name was appended to that of her husband. It is not known where the title "Baronne" came from. Did it come from her husband or was the title acquired by her in her own right? She was known as Baronne De Wulf.
Bibi was a very successful milliner. She had a shop in Paris on the corner of rue du Faubourg St. Honoré and rue Gambon. This was very close to Place Vendôme, which is still the smartest district of Paris. Her niece, Marie (Marion) Berbuto worked for her there. She made a lot of money which enabled her to buy the land 'sur la Corniche de Rolleboise' on which the château was constructed. Bibi was known in the family as "Tante Riche"
Le Château de Rolleboise was built by Baronne Bibi Vallée-De Wulf
and not by King Leopold II